I am not a cold-water person. My wife jokes about it every time we hit a beach, because my first walk into the sea takes a good five or ten minutes of flinching. So take it from a wimp: on my first boat dives here, in the middle of May, a 3mm shorty was perfect and the water never once bothered me.
Cozumel’s water temperature barely moves all year. It sits around 79°F (26°C) in the cool months from January to March and climbs to about 85°F (29°C) at the late-summer peak in August and September, a swing of only about 6°F.
Visibility holds at 80 to 100+ feet (24 to 30+ m) and goes glassiest from December to May. The current is the one condition that shapes your day. Cozumel is a drift-diving island, so most dives you stop kicking and let the water fly you along the reef, though the far-north and far-south sites can run hard.
Hurricane season runs June 1 to November 30 and peaks in mid-September, but a direct hit is rare. Most divers are comfortable in a 3mm wetsuit all year, lightening to a rashguard or shorty in summer. The chart below is the quick reference, and each condition gets its own section underneath.
1. Cozumel diving conditions at a glance
Every figure here is a long-term average, not a promise for any single day. The sources are in the caption below. Each is also linked inline where the condition is discussed.
| Month | Water | Air | Visibility | Current | Storm risk | Crowds | Suit |
|---|---|---|---|---|---|---|---|
| January | 79°F (26°C) | 81°F (27°C) | Excellent | Moderate | None | Very high | 3mm wetsuit |
| February | 79°F (26°C) | 83°F (28°C) | Excellent | Moderate | None | High | 3mm wetsuit |
| March | 80°F (27°C) | 84°F (29°C) | Excellent | Easy | None | Very high | 3mm wetsuit |
| April | 81°F (27°C) | 87°F (31°C) | Excellent | Easy | None | High | 3mm wetsuit |
| May | 82°F (28°C) | 88°F (31°C) | Very good | Calm | Very low | Mid | Shorty |
| June | 83°F (28°C) | 87°F (31°C) | Good | Calm | Low | Low | Shorty |
| July | 84°F (29°C) | 89°F (32°C) | Good | Calm | Moderate | Low | Rashguard |
| August | 85°F (29°C) | 89°F (32°C) | Good | Calm | High | Low | Rashguard |
| September | 85°F (29°C) | 88°F (31°C) | Variable | Easy | Peak | Minimal | Rashguard |
| October | 84°F (29°C) | 86°F (30°C) | Good | Variable | High | Low | Shorty |
| November | 82°F (28°C) | 83°F (28°C) | Very good | Moderate | Low | Mid | 3mm wetsuit |
| December | 81°F (27°C) | 82°F (28°C) | Excellent | Moderate | None | High | 3mm wetsuit |
2. Water temperature month-by-month, with thermocline notes
Cozumel’s water temperature ranges from about 79°F (26°C) at the February low to 85°F (29°C) at the September peak. That is a swing of only about 6°F (about 3°C) across the whole year. By tropical-diving standards, it never gets cold.
| Month | Avg surface temp | Typical range | Note |
|---|---|---|---|
| January | 79-80°F26-26.5°C | 78-81°F25.5-27°C | Cooling continues; among the clearest-visibility months |
| February | 79°F26-26.4°C | 78-80°F25.5-26.5°C | Coolest water of the year |
| March | 79-80°F26.5°C | 78-80°F25.5-26.5°C | Still cool; warming not yet underway |
| April | 80-81°F27°C | 80-81°F26.5-27°C | Gentle warming begins |
| May | 82°F28°C | 80-83°F26.5-28.5°C | Noticeable climb |
| June | 83°F28.5°C | 82-84°F28-29°C | Comfortable warmth |
| July | 84°F28.8°C | 83-84°F28.5-29°C | Warm |
| August | 84-85°F29.2°C | 84-85°F29-29.5°C | Near the annual peak |
| September | 85°F29.3°C | 84-85°F29-29.5°C | Warmest water of the year |
| October | 84°F29°C | 83-85°F28.5-29.5°C | Still very warm |
| November | 82-83°F28°C | 81-84°F27-29°C | Slow cool-down |
| December | 81°F27.3°C | 80-82°F26.5-28°C | Cooling toward the winter low |
Different sources give slightly different numbers, so do not over-read them. Plan for the upper 70s°F (mid-20s°C) in winter and the mid-80s°F (around 29°C) in late summer.
What it feels like at depth
Cozumel rarely forms a sharp, stable thermocline, the depth where the water turns abruptly colder and stays that way. The reason is the current. Cozumel is a high-current drift destination, and that constant motion keeps the water column mixed. Mixing works against the layering a hard thermocline needs. Most longtime local divers say they almost never hit a dramatic cold layer, the way you would in a lake or a calmer sea.
In practice, deeper reef sites run about 2 to 3°F (1 to 2°C) cooler than the surface, and the change is gradual rather than a wall of cold. Divers’ computer logs bear this out. In January and February, the surface average sits near 79 to 80°F (26 to 26.5°C), and reef minimums at 60 to 90 ft (18 to 27 m) read 77 to 79°F (25 to 26°C). The rule is simple. Take the surface number, subtract a degree or two. That is roughly what you feel deep on the wall.
Mixed, though, is not the same as uniform. The same current that prevents a clean thermocline can also stir cool and warm water together. So instead of one tidy cold layer, you may pass through patchy, shifting pockets. On an unusual day, those swings can be pronounced.
I felt exactly that on one boat dive at Tormentos. The temperature kept changing: warm, then suddenly cool, then back again, more than I expected for a single dive. Afterward at the shop, my instructor told another divemaster that in 300 dives he had never felt swings quite like it. It clearly was not a normal day. And that is the point. The rule here is gentle and gradual, but once in a while the water surprises even the people who dive it every day.
You are more likely to swim through a halocline than a cold layer. It is a shimmering, oily-looking boundary where lighter freshwater sits over saltwater. It can show up after heavy rain or near freshwater seeps. It blurs your vision for a moment, but it is not a cold shock. And a strong tropical system can briefly mix cooler deep water toward the surface. That can pull temperatures down a few degrees for a day or two, before they rebound to the seasonal average.
3. Visibility, when it is at its best and when it is not
Visibility in Cozumel runs 80 to 100+ feet (24 to 30+ m) on a normal day. On the clearest winter days it goes well beyond that. Clear water is the other half of the island’s reputation, alongside the current. Few places in the Caribbean match it, and the reason is geology, not luck.
What good visibility means here. A genuinely poor Cozumel day is still around 80 ft (24 m). That beats the best day at many dive spots. In the dry season it routinely tops 100 ft (30 m), and the best days reach roughly 130 to 150 ft (40 to 46 m). You will see operators advertise 150 to 200 ft. Treat 200 ft (60 m) as a rare ceiling and marketing hype, not a planning number.
When it is at its best. Visibility tracks the dry season. The clearest stretch runs December through May, when rainfall is lowest and the water column is settled. In those months 100+ ft (30+ m) is the norm. That overlaps with the cooler-water, eagle-ray season, which is why winter is peak season for serious divers.
When it dips, and how fast it recovers. Three things knock visibility down, all temporary:
- Heavy rain. Summer and early-fall downpours can briefly cloud the surface layer and nearshore areas. Because Cozumel has no rivers (see below), the effect is limited and short-lived.
- Storms and big swell. A tropical system or a strong norte stirs sediment and can drop visibility for a day or two. The Yucatán Current then flushes the channel, and clear water typically returns within about 48 hours.
- Plankton and season. The warmest months, roughly July to October, carry a bit more plankton and rain. So summer visibility averages a notch below the winter peak. It is still very good, just less reliably 100+ ft. Spring is often the sharpest.
Why Cozumel is so clear. Three mechanisms stack up:
- No rivers. Cozumel is a flat, porous limestone (karst) island. Rain sinks straight down through the rock into underground aquifers and cenotes before it can form streams or rivers. So almost no muddy runoff reaches the reefs.
- Clear oceanic water and constant flushing. The reefs sit in open, nutrient-poor (oligotrophic) Caribbean water that carries little plankton. The Yucatán Current sweeps the west-coast shelf without stopping. It carries particles away and replaces them with clean blue water.
- White sand and a leeward coast. Bright carbonate-sand bottoms reflect light and lift apparent visibility. The west coast is sheltered from the prevailing easterly trade winds, so the water is usually flat and calm.
Does sargassum hurt the diving? Short answer: not the diving. Sargassum is a surface seaweed that drifts onto the windward east coast and its beaches. Cozumel’s dive sites are all on the sheltered west coast, and underwater, below the floating weed. Even in heavy sargassum years, west-coast dive operations run normally. Visibility at the reefs is set by current and weather, not by sargassum. Beach snorkeling on an affected east-side beach is a different story.
4. Currents, Cozumel’s defining condition, by season
If you remember one thing about diving Cozumel, make it this: almost every dive is a drift dive. You do not swim the reef so much as fly along it while the current does the work. That current is the engine behind everything Cozumel is famous for. Learning to relax into it is the whole skill.
If you have never dived before, a guided first dive teaches you exactly this. And you can do it with no certification at all. I cover that in scuba diving without certification and in my own first dives.
What drives it. Cozumel sits in the path of the Yucatán Current. That powerful flow funnels warm water north out of the Caribbean, between the Yucatán Peninsula and Cuba. From there it becomes the Loop Current and, eventually, the Gulf Stream.
The flow then squeezes through the Cozumel Channel, the deep gap between the island and the mainland. There it speeds up. Oceanographers measured a mean surface current of about 1.1 m/s (roughly 2 knots) at 30 m (100 ft) depth. The current intensifies as it passes the island. That funneling is why a small island gets such reliable, sometimes ripping, drift.
Which way it flows. Along Cozumel’s west-coast reefs, the current runs mostly south to north. That is why drift dives are planned the way they are. The boat drops you at the south end of a reef, you drift north along it, and it follows your bubbles to collect you wherever you surface. The direction is consistent and the reef nearly continuous. So even a strong day usually just means a faster, longer glide, not something to fight.
How strong, by site. Current is the main thing separating an easy Cozumel site from an advanced one. As a rule, the southern and central reefs are gentler and the northern sites are stronger. Within any site, the deeper water runs faster than the shallows.
- Gentle and beginner-friendly: Paradise Reef, Chankanaab, Villa Blanca, Las Palmas, San Francisco, Columbia Shallows, Tormentos. Mild, relaxed drift; good first-dive-in-Cozumel sites.
- Moderate: Yucab, Paso del Cedral, Punta Tunich, La Francesa, Palancar, Santa Rosa Wall on a calm day. A noticeable, flying drift.
- Strong and advanced: Santa Rosa Wall when it is running, Colombia Deep, Punta Sur. Reliable, quick current; comfortable buoyancy and good air consumption assumed.
- Expert only, far south and far north: Punta Sur’s Devil’s Throat and Cathedral, Maracaibo at the southern tip, and the northern sites of Barracuda, San Juan and Cantarel. Here the deeper sites can run a few knots. Reliable reports put the far-north sites at around 3 knots and occasionally 6 knots or more. That is far faster than anyone can swim against. Several operators require two or more prior dives with them first. Only then will they take you to Punta Sur, Maracaibo, or anything north of the harbor.
What it feels like, and where the real hazards are. A typical Cozumel drift is gentle. You hold position with your breathing and small fin adjustments and let the reef scroll past. The real hazards are not a wall of cold or a sudden down-current. Cozumel’s current is overwhelmingly horizontal, not the downwellings some wall destinations get.
The genuine risks are three. First, separation: at the fast northern sites, drifting from the group can mean being carried off the end of the reef into open water. Second, the overhead, deep environment at Devil’s Throat and Cathedral, where the tunnels sit at 80 to 135 ft (24 to 41 m), right at recreational limits. Third, surface conditions at exposed southern sites like Maracaibo, where swell and wind can make the day rough topside.
None of this is a reason for a competent diver to stay home. It is a reason to dive the right site for your level on the right day.
A note from the water. My own strongest taste of this came at Tormentos, a site most operators rate as gentle. It is a useful reminder that current in Cozumel is a day-to-day call, not a fixed property of a site. That day the drift was strong enough that swimming against it was simply not an option. With other divers nearby, I had to keep adjusting just to avoid bumping into anyone. If I wanted a closer look at something, I had to start moving toward it well in advance, because once you pass a point there is no going back. You are a passenger on a ride with no stops. Within a few minutes I had the feel of it: no kicking at all, just small shifts of the body to steer, and a harder kick only when I wanted to cross the flow.
The drift-diving playbook, Cozumel norms.
- Go with the flow. Never fight the current. Stay roughly 6 ft (2 m) off the reef, keep your body streamlined, and tuck behind coral structure if you want to slow down.
- Negative entry only where it is needed. At most sites you giant-stride in, regroup at the surface, and descend together. A few sites use a negative entry, which means you deflate and drop right away. Cathedral and Devil’s Throat especially do this. The group then reaches the cavern entrance together instead of being swept past it.
- Surface marker buoys are standard. With many boats working the same drift, your divemaster usually deploys an SMB before the group ascends, so the captain and other boats can spot you. If you own a safety sausage, bring it as a backup in case you get separated in strong current.
- Trust the morning call. There is no fixed daily schedule in Cozumel. Each morning the captain and divemaster read current, wind and sea state and pair sites to conditions and to the group’s level. The captain has the final say.
Is there really a current season? Less than you might think. Current strength in Cozumel is mostly a day-to-day, site-by-site variable. It is governed by the Yucatán Current’s mesoscale swings (the Loop Current’s eddy cycle) rather than a tidy calendar.
That said, two real tendencies are worth planning around. The autumn-and-winter transition, roughly November to March, tends to bring livelier, more variable current. Not coincidentally, this is when the deeper sites fill with eagle rays (peaking mid-January to early March) and bull sharks, which ride the moving water. Late spring through summer, roughly May to September, tends to be the calmest, flattest stretch.
Weather can override the calendar. The roughest west-coast days in winter come from nortes, the cold fronts out of North America. They blow onto the normally sheltered west coast and turn the calm channel into chop. These fronts are the main reason winter diving sometimes gets called off. The mechanics of nortes and port closures belong with the weather, so they are covered in section 5.
For current, the rule of thumb is simple. A winter norte is what most often turns an easy drift into a rough, pushy day. And very rarely, a major storm can briefly reverse the current from north to south for a day or so before it settles back.
5. Weather and storm risk, the hurricane window (June to November) and crowd implications
Cozumel diving runs all year, hurricane season included. The Atlantic season is real and worth planning around. But the data-backed picture is reassuring. A direct hit on Cozumel is a once-in-a-decade-or-two event. Most of the storm season is simply warm, humid weather: a heavy shower or two a day, with excellent diving in between.
The season, and when risk peaks. The Atlantic hurricane season runs June 1 to November 30. For Cozumel, the riskiest stretch is mid-September to early October. June, July and early November are the quiet edges of the window. So if you are booking inside hurricane season, the shoulders are the safer bet.
How rare a real hit is. A direct hit is genuinely rare. A hurricane passes within 60 nm of Cozumel only about once every 25 to 34 years, even in the peak September week, and a major one far less often. Cozumel sits south of the corridor most Atlantic storms follow into the Gulf of Mexico, and many that reach it have already weakened. Serious direct hits are decades apart: Gilbert in 1988, Emily and Wilma in 2005. Most years bring only glancing blows. For a dive trip, the takeaway is that a storm actually wrecking your week is a long shot. A closed-port day or two is the more likely disruption.
This season’s outlook (2026). Each year’s forecast matters more than the long-run odds. For 2026, NOAA forecasts a below-normal season. A developing El Niño should keep activity down through the peak. Colorado State University puts the chance of a major hurricane reaching the Caribbean at about 35%, below the long-term 47%. A quiet forecast is never a guarantee, but 2026 is shaping up calmer than the busy recent years. (Living-document note: I refresh this each spring when NOAA’s outlook lands; figures are from the May 2026 outlook.)
What the weather is like topside. Cozumel has two seasons: a drier, cooler one from November to April, and a muggy rainy one from May to October. Even in the rainy season it rarely pours all day. The usual pattern is one or two short, heavy downpours with sunshine the rest of the time. The wettest, stormiest stretch is September and October. Sunshine averages about 7 hours a day year-round. For diving, none of this matters much once you are under. But rain and wind can knock surface visibility down (see section 3) and make the boat ride between dives less pleasant.
Nortes, the winter weather story. From roughly mid-November to mid-March, nortes (cold fronts out of North America) sweep down with strong north winds. They can drop nighttime temperatures to 68 to 72°F (20 to 22°C). On the sharpest fronts they reach the low 50s°F (around 11°C). Those winds blow onto the normally sheltered west coast, where the dive boats run. They are the main cause of winter port closures.
When a front is strong enough, the Capitanía de Puerto (the port captain) closes the harbor to all small boats. The typical triggers are sustained winds over about 18 knots, or channel waves around 4 ft (1.2 m), with SEMAR’s marine forecasts feeding the decision. A closure halts all diving, snorkeling and water sports until the wind drops, usually a day or two. So the same fronts that bring the year’s coolest, breeziest days are also the ones most likely to cancel a dive day.
Crowds, and what they mean underwater. The weather calendar and the crowd calendar are mirror images. Peak tourist season is the dry, cooler stretch from mid-December through April. On the busiest days, five to eight cruise ships fill the popular dive sites and downtown. The reefs can feel crowded with other groups.
The hurricane months, especially September and October, are the quietest of the year. Reefs are noticeably emptier, and last-minute spots are easier to get. May and November are the comfortable middle. How that maps onto prices, deposits and when to book is the subject of section 7.
6. What to bring, wetsuit thickness by month and exposure protection
The short answer fits in one line: for most divers, a 3mm wetsuit works in Cozumel all year. Lighten to a rashguard or shorty in the late-summer warmth. Add a hood or a thicker suit in winter only if you feel the cold. The rest of this section is the detail behind that line, plus the exposure gear that matters more than thickness here.
Wetsuit thickness by water temperature. The standard dive-industry guide maps neatly onto Cozumel’s 79 to 85°F (26 to 29°C) range. At 80 to 85°F (27 to 29°C), warm-blooded divers are fine in a dive skin or 2mm shorty, while cold-prone divers want a 2 to 3mm fullsuit. At 73 to 79°F (23 to 26°C), the guide calls for a 3mm fullsuit, up to 5mm for those who chill easily. Cozumel never leaves that band, so 3mm is the do-everything default. Nobody needs a 5mm-plus suit or a drysuit here.
| Month | Water temp | Most divers | If you feel the cold or do 3+ dives a day |
|---|---|---|---|
| Jan-Mar | 79-80°F26°C | 3mm full | 5mm full, or 3mm plus hooded vest |
| April | 80-81°F27°C | 3mm full or shorty | 3mm full |
| May-Jun | 82-83°F28°C | 3mm or shorty | 3mm full |
| Jul-Oct | 84-85°F29°C | Rashguard, dive skin, or shorty | 3mm shorty or full |
| November | 82-83°F28°C | 3mm or shorty | 3mm full |
| December | 81°F27°C | 3mm full | 3mm plus hooded vest |
Why you may feel cooler than the number suggests. Two things make the water feel cooler than the surface reading, and neither is a thermocline (see section 2). The first is cumulative heat loss. One dive feels warm, but over two or three dives a day the chill creeps in. That is why even local divemasters wear a 3mm in January, and many add a hooded vest for the third dive.
The second is depth. Neoprene compresses as you descend: a 3mm suit loses roughly half its insulation by 33 ft (10 m), and more below that. So the suit that is cozy in the shallows feels thinner on a deep wall. If you run cold, a hooded vest under a 3mm is the single most efficient add-on.
For what it is worth, I feel the cold more than most, and my own May dives still held up fine. At Tormentos, the temperature noticeably switched between warm and cool mid-dive. Even so, a 3mm shorty kept me comfortable the whole way through.
Exposure protection matters more than warmth here. In water this warm, the bigger reasons to cover up are sun, stingers and coral.
- Sun. Cozumel is at 20°N with strong tropical sun, about 7 hours a day. A UPF rashguard or dive skin is the smart base layer, partly because of the sunscreen rule below.
- Reef-safe sunscreen, and the Marine Park ban. The Cozumel Reefs National Marine Park prohibits non-biodegradable sunscreen. In practice, most operators ban all sunscreen in the water to protect the coral. The workaround: cover up with a rashguard, and put reef-safe, biodegradable sunscreen (brands like Stream2Sea or Safe Sea) on exposed skin on land only. Avoid oxybenzone, octinoxate and PABA, or skip sunscreen in the water entirely.
- Fire coral and brushing the reef. A full-skin layer also guards against fire coral and the inevitable accidental reef brush. Fire coral is a mustard-colored, hydroid-family stinger that is easy to mistake for harmless seaweed.
- Sea lice (pica-pica), mainly late spring. The larvae of the thimble jellyfish cause seabather’s eruption, locally called pica-pica. It is an itchy rash on covered skin, harmless but annoying. It breeds across the Caribbean through summer and peaks around May and June. The counterintuitive part: the larvae get trapped under swimwear. So the best defense is rinsing off and changing out of your suit promptly after diving (a barrier cream like Safe Sea helps too). DAN’s first aid is to rinse with vinegar and apply heat.
The Marine Park gear rule that surprises people: no gloves. Inside the park, gloves and knives are prohibited for recreational divers (registered pros excepted). The rule exists to discourage touching the reef. So if you are coming from cold-water diving, leave the gloves at home, because you will not be allowed to use them. The park also requires a guided dive, with a maximum of 8 divers per guide. It charges a per-day Marine Park fee too, usually added to your dive price. The current amount and how to budget for it are in section 7.
A few non-suit items worth packing.
- A windbreaker, towel, or poncho for the boat. You are wet, and the breeze between dives is chilly even when it is hot out, especially on winter norte days.
- Your certification card, and dive insurance if you have it (see section 8).
- A safety sausage or SMB if you own one. Your divemaster carries one for the group, but your own is a useful backup if you get separated in a strong current, so a boat can still spot you (see section 4).
Tanks and weights come with every dive, so you never pack those. Almost every shop also rents full gear (mask, fins, wetsuit, BCD, regulator) for around $35 a day, with a dive computer usually about $10 more. Pack only the personal kit you prefer to own, and rent the rest.
7. Booking implications, when to book and when to be flexible
Once you understand Cozumel’s conditions calendar, the booking strategy almost writes itself. Book early for the clear-water high season. Stay flexible, and pay less, in the low-crowd hurricane months. And whenever you come, build a little slack into your dive days, so a closed port does not sink the whole trip.
When to book well ahead. The island’s busiest, clearest-water stretch is roughly mid-December through April. That is also when the best operators fill up. The window covers the Christmas and New Year holidays, Mexican Carnival, and North American spring break. For those dates, long-running shops advise reserving about two months ahead.
Even outside the holiday peaks, the strongest small operators run limited boats of six to eight divers. They sell out their best days. So booking three to four weeks out is sensible any time in high season. If you have your heart set on a particular shop, boat, or nitrox, reserve earlier rather than later.
When you can be flexible, and save. The flip side of the hurricane calendar is the bargain. September and October, and to a lesser degree June through August, are the cheapest, least-crowded months of the year. Lodging often runs well below peak rates, and the reefs are noticeably emptier.
Dive operators rarely discount the dives themselves. But multi-day packages, dive-and-stay deals, and easy last-minute availability are common in the low season. If your dates are movable and you do not mind a daily rain shower, booking closer in is low-risk. May and November are the sweet spot: warm water, thinner crowds, lower prices, and storm risk still low.
Spread your dives across several days, the step most visitors skip. Cozumel diving can be shut down on short notice when the port captain closes the harbor. That happens most often with a winter norte (November to March) or a passing tropical system (June to November), as explained in sections 4 and 5. A closure usually lasts only a day or two. But if your single planned dive day lands on a closed-port day, that is your trip.
Budget for the extras. Quoted dive prices usually exclude two add-ons. The first is the Marine Park fee: a federal charge of 218.32 pesos, roughly $13 USD, per person per day, set by CONANP. The second is Mexican tax (IVA, 16%), which some shops add on top. Factor both into your real per-day cost.
Which month is best for your trip depends on what you want: the warmest water, the sharpest visibility, the fewest crowds, or the eagle-ray season. I work through that month by month in the best-time-to-dive guide.
8. Insurance and cancellation policies in the hurricane window
What follows is general information to help you read a policy, not financial, legal, or insurance advice.
Weather closures are almost always covered. The most reassuring policy clause is also the most consistent. If the Capitanía de Puerto (the port captain) closes the harbor for weather, nearly every operator reschedules your dives or refunds you. That covers a norte or an approaching storm. A closed port is the most likely reason diving gets cancelled, and the one cancellation you are protected against at no extra cost.
Your own cancellation varies widely. Cancelling for any other reason is where terms vary. Across the operators we surveyed, full-refund windows run from 24 hours to 30 days before your dive. Deposits are commonly around $50 a day. The big resort operators prepay and lean on multi-year vouchers rather than cash. Most shops will not refund for illness, seasickness, a no-show, or a missed cruise-ship port. That gap is exactly what travel insurance covers.
Two kinds of insurance are worth knowing about.
- Dive-accident insurance, such as DAN, covers diving-specific costs like recompression-chamber treatment. Standard health and travel policies often exclude those. It is cheap, from around $40 a year, and worth it for any diver.
- Travel insurance with trip-interruption coverage reimburses prepaid, non-refundable costs. It applies when you cancel or cut a trip short for a covered reason. If your dates fall in the hurricane window and you have prepaid flights and lodging, that is when it earns its cost.
For the full operator-by-operator comparison, see our guide on how to choose a Cozumel dive shop.
Frequently asked questions
What is the water temperature in Cozumel?
Cozumel’s water temperature ranges from about 79°F (26°C) at the February low to 85°F (29°C) at the September high. That is a swing of only about 6°F (3°C) across the year. Winter, January to March, sits in the upper 70s°F (mid-20s°C). Late summer, August and September, reaches the mid-80s°F (around 29°C). The month-by-month figures are in section 2.
Do you need a wetsuit to dive in Cozumel?
For most divers, a 3mm wetsuit works year-round. In the late-summer warmth, roughly July to October, many switch to a rashguard or shorty. In winter, cold-prone divers add a hooded vest. Nobody needs a 5mm-plus suit or a drysuit here, because the water never leaves the upper-70s-to-mid-80s°F (mid-20s-to-29°C) band.
Is there a thermocline in Cozumel?
Rarely a sharp, stable one. The strong current keeps the water column mixed. So most divers feel only a gentle degree or two of cooling at depth, not a defined cold layer. On unusual days the current can stir up patchy temperature changes. But a hard thermocline, like you get in a lake or a calmer sea, is uncommon here.
How strong are the currents in Cozumel?
Most dives are an easy, flying drift from south to north, where you let the current carry you along the reef. The southern and central reefs are gentler. The far-north sites are the strongest, with reliable reports of around 3 knots and occasionally 6 knots or more. That is far faster than anyone can swim against. Current is the main thing that separates a beginner site from an advanced one.
What is the visibility like for diving in Cozumel?
Expect 80 to 100+ ft (24 to 30+ m) year-round, and often beyond 100 ft (30 m) in the dry season from December to May. Even a poor Cozumel day is around 80 ft (24 m). The clarity comes from three things. The island has no rivers. It sits in clear, open ocean water. And the Yucatán Current constantly flushes the reefs.
Does sargassum affect diving in Cozumel?
Not the diving. Sargassum is a surface seaweed that washes onto the windward east coast. Cozumel’s dive sites are all on the sheltered west coast and underwater, below the floating weed. West-coast dive operations run normally even in heavy sargassum years. Beach snorkeling on an affected east-side beach is a different story.
When is the best time to dive in Cozumel?
It depends on the trade-off. December to May brings the clearest water and the biggest marine life, but the largest crowds and highest prices. September and October are the cheapest and quietest, but the wettest, and the peak of hurricane risk. May and November are the sweet-spot shoulder months. A full month-by-month recommendation, sorted by what you value most, is its own guide.
What happens to my dive booking if there is a hurricane in Cozumel?
If the port captain closes the harbor for weather, nearly every operator reschedules or refunds you. A closed port is the one cancellation you are protected against. Cancelling for any other reason varies by operator. Full-refund windows run from 24 hours to 30 days.
Can you wear gloves diving in Cozumel?
No. Gloves and knives are prohibited for recreational divers inside the Cozumel Reefs National Marine Park. The rule discourages touching the reef, and registered pros are the exception. If you dive cold water elsewhere, leave the gloves at home. You will not be allowed to use them.
Last verified: June 2026. This is a living document; I update it when the data, the operators’ policies, or my own observations change.
A note on what this article is: a conditions reference built from public data and my own diving in Cozumel, not a paid recommendation. DripDive is independent and no operator paid for any mention. Where a dive shop is named as a source of conditions or policy data, it is cited as a source, not endorsed.
More on DripDive: Discover Scuba in Cozumel: My First Two Days Underwater and Can You Scuba Dive Without Certification in Cozumel?
