Seasonal
The sea here never gets cold. It does get cold enough, in February, that divers who packed a rash guard and nothing else regret it on the second tank.
Cozumel's sea temperature moves through a narrow band, roughly the high seventies to the mid eighties Fahrenheit, and never approaches cold. What changes is how long you can stay in it, which matters more on a second dive than on a snorkel.
Figures below are rounded monthly normals, not forecasts.
| Month | Sea temp (°F) | Typical exposure protection |
|---|---|---|
| January | around 80 | 3mm full suit for most divers |
| February | around 79 | 3mm; the coolest month of the year |
| March | around 80 | 3mm, or a shorty if you run warm |
| April | around 81 | 3mm or shorty |
| May | around 83 | Shorty, or a rash guard and skin |
| June | around 84 | Rash guard for most |
| July | around 84 | Rash guard |
| August | around 85 | Rash guard |
| September | around 85 | Rash guard; warmest of the year |
| October | around 84 | Rash guard |
| November | around 82 | Shorty as the fronts start |
| December | around 81 | 3mm as the water turns over |
Three Cozumel-specific reasons.
You are not working. This is a drift island. The current does the moving, so you generate very little heat, and a passive diver cools faster than one finning.
Profiles are long. Second dives here routinely run forty to fifty minutes or more because air consumption is good when you are not swimming. That is a long time at 79 degrees.
Repetitive multi-day diving compounds it. Day four of two-tank mornings feels colder than day one at the same water temperature. Experienced Cozumel regulars pack a suit one step warmer than the table suggests for exactly this reason.
And the wind. Between November and March, a wet body on an open boat between tanks in a norte is the coldest you will be on this trip. A windproof layer for the surface interval is worth more than an extra millimetre of neoprene.
A rash guard year-round, mostly for sun rather than heat. Between eleven and three the UV here sits near the top of the scale, and a long-sleeved vest solves burn without putting anything in the water. A shorty is worth having in January and February if you plan long sessions.
Visibility is high all year, because the same current that carries you is constantly flushing the reef with clean open-ocean water. Temperature is the variable here. Clarity is not.
SourcingSea temperatures are rounded monthly normals for Cozumel consistent with the figures used across this destination's profile, and are presented as normals rather than forecasts. Individual days vary, particularly during winter frontal passages. Exposure protection recommendations are general guidance; take advice from your dive shop for the conditions on the day.
Plan around it
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Newsroom
Seasonal
The difference between a February week and a September week here is not only money. It is how many ships are in, how busy Palancar is, and what is shut.
Seasonal
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