If you want tomorrow's forecast, use a forecast app, we are not going to pretend to beat one. What you cannot get from a widget is the thing you actually need when you are booking six months out: what a normal week in March looks like versus a normal week in September, how warm the water really is, when the rain shows up and how long it lasts, and which months carry hurricane risk worth insuring against. That is this page, every month, with the numbers and the honest read.
Hot, rainy, or windy does not ruin Cozumel. The wrong hotel does.
Best in the dry months when you want to be in the water
When the forecast is the reason you came, stay on the sheltered west coast. That is the calm water, the beach clubs, and the snorkel boats. The east side is for a drive, not a hotel week.
Best in rainy or sargassum weeks
When the sea is chopped up or the seaweed shows, the week is the pool. Filter for hotels that actually have one, not a plunge tub next to the bar.
Cozumel is warm every single month. Average highs never drop below about 81F and never climb past about 90F, and the sea sits between roughly 79F and 85F all year, which means you will never need a wetsuit to snorkel and rarely want more than a thin one to dive. Nobody comes here and gets cold. The temperature barely moves all year. What changes is how much water falls out of the sky and how hard the wind pushes the sea around. Roughly speaking: February through April is the dry, bright, flat-water stretch, May through August is hot and humid with short afternoon downpours, and September through October is the wet, cloudy, hurricane-peak window that is also the cheapest time to be here by a wide margin. November and December dry back out. The averages hide the nortes. Winter can throw a north wind that kicks up chop for a day or two and pushes the dive boats to the sheltered southwest side. It is not a forecast you can plan around, just a thing that happens, and the southwest sites are where most of the good stuff is anyway.
Average daily high and low, approximate sea temperature, and what the sky is actually doing. Use this to set expectations, then check a real forecast about ten days out.
| Month | Average high / low | Sea temp | Rain and sky | What it actually feels like |
|---|---|---|---|---|
| January | 81F / 66F | About 79F | Dry, the odd norte wind | Peak season and it earns it. Warm days, evenings cool enough for a shirt. Best weather odds of the year, and priced like it. |
| February | 82F / 66F | About 79F | The clearest skies of the year | Statistically the best month here: driest stretch, clearest skies, flattest seas, best underwater visibility. Also the busiest and priciest. |
| March | 84F / 66F | About 79F | Driest month, about 1.2in of rain | Bright, dry, still comfortable. Spring break crowds land mid-month and the cruise piers get busy. |
| April | 86F / 68F | About 80F | Fewest rain days of the year, about 4.3 | The quiet sweet spot. Warm, dry, thinner crowds, better rates. Sargassum starts appearing on the east side late in the month. |
| May | 88F / 72F | About 82F | Humidity builds, first real showers | Hot, and the water is genuinely bathwater. Still mostly dry. Locals' pick for value before summer prices and weather arrive. |
| June | 88F / 73F | About 83F | Hurricane season opens, afternoon showers | Humid. The rain is usually a hard 30 minutes in the afternoon, not an all-day washout. Family season begins. |
| July | 90F / 72F | About 84F | Hot, quick afternoon rain | Tied for the hottest month. Flat, glassy sea most days, which divers love. Sargassum risk is real on the windward side. |
| August | 90F / 72F | About 84F | Hot and humid, peak sargassum risk | Same heat as July with worse seaweed odds. The southwest beach clubs still read clear, see sargassum in Cozumel. |
| September | 88F / 72F | About 84F | Cloudiest month, most rain days, about 15.9 | Hurricane peak and the cheapest month of the year. Warm water, gray skies, real storm risk. Buy insurance, keep plans loose. |
| October | 86F / 72F | About 83F | Wettest month by volume, about 5.6in | Still hurricane season, still cheap, starting to ease off. Sargassum fades. A gamble that often pays. |
| November | 84F / 70F | About 81F | Drying out, seas settling down | The underrated month. Shoulder prices, thinner crowds, weather turning good again. Season officially ends November 30. |
| December | 82F / 66F | About 80F | Dry, nortes possible | Lovely weather. Prices and crowds are reasonable until about the 15th, then the holidays hit and everything doubles. |
Temperature normals and the rain and cloud extremes come from WeatherSpark's San Miguel de Cozumel station. Sea temperatures are approximate, taken where WeatherSpark and the island's dive operators agree. Only months a source actually quantifies carry a rainfall number; the rest get an honest qualitative read rather than an invented figure.
People read 'rainy season' and picture a washed-out week. That is not how it works here. From roughly June through October the pattern is a hot, bright morning, clouds stacking up after lunch, then a hard downpour that empties the sky in half an hour and leaves everything steaming. You lose an afternoon hour, not a day. Boats mostly still run, beach clubs stay open, and the rain is warm. The exception is September and October, when the systems get bigger and slower. September is the cloudiest month and averages the most rainy days of the year at about 15.9, and October dumps the most total water at around 5.6 inches. That is when you can genuinely lose a day, or when a storm sitting somewhere else in the Caribbean pauses the ferries and the dive boats for a stretch without ever hitting the island itself. If you are diving or snorkeling, rain matters far less than you would think. The water is warm regardless, and surface rain does not touch visibility down on the reef. Wind is the thing that cancels a boat day, not rain.
Atlantic hurricane season officially runs June 1 through November 30, but the months that actually keep people watching the radar are September and October. A direct hit on Cozumel in any given year is uncommon, and the island is well drilled for it when it happens. The much more likely disruption is indirect: a storm anywhere in the region kicks up seas, and suddenly the Playa del Carmen ferry is cancelled and the dive boats are tied up for two or three days while the sky over you looks perfectly fine. That is the risk you are actually pricing when you book September or October, and it is why those months are cheap. It is a reasonable trade if you buy travel insurance, keep the itinerary loose, and do not schedule the one thing you came for on your last day. It is a bad trade if this is a once-in-a-decade trip with a fixed plan. For how that risk stacks against crowds and price, see the best time to visit Cozumel.
The sea runs from about 79F in the late-winter low to about 85F at the late-summer peak. In practical terms: snorkelers never need anything, and most divers are comfortable in a 3mm shorty or skin year round, with a full 3mm being plenty for the coolest months if you run cold or are doing three tanks a day. Visibility is the other number divers ask about, and Cozumel is spoiled here. It generally runs 80 to 100 feet or better all year, with the clearest stretch falling roughly December through May. Summer tends to bring the flattest, glassiest surface conditions. There is no bad season to dive here, which is the whole reason the island has the reputation it has, see the scuba diving guide for what that actually gets you.
Temperature normals and the rain and cloud extremes are WeatherSpark's figures for the San Miguel de Cozumel station, which is the closest long-run record to where you will actually be standing. Sea temperatures are stated as approximate on purpose: WeatherSpark and the island's dive shops publish slightly different values, so we use the range where they agree rather than picking a precise-looking number that only one source supports. We deliberately do not print a rainfall figure for every month, because we could only source four of them honestly; the other eight get a qualitative read instead of a number we would have had to make up. Averages are not a forecast, so check a real one about ten days out and treat this page as what to expect, not what will happen.
Very good, which is why the month gets expensive. Average high around 82F and low around 66F, sea around 80F, and it is one of the drier months. The main variable is a norte, a north wind that can bring a day or two of chop and push dive boats to the sheltered southwest side. Weather-wise the first half of December is the sweet spot: the same conditions as the holidays without the holiday pricing, which kicks in around the 15th.
Warm days, cool evenings, and the best weather odds of the year alongside February. Average high about 81F, low about 66F, sea about 79F. It is dry, the seas are generally flat and the underwater visibility is excellent. This is peak season, so you are paying for that reliability in room rates and sharing the island with the heaviest cruise traffic of the year.
Statistically the best month on the island. February is the clearest month of the year, with the driest conditions, flattest seas and the best diving visibility. Average high about 82F, low about 66F, water about 79F. The catch is that everyone else knows it too, so February is the busiest and priciest window along with January.
March is the driest month of the year, averaging only about 1.2 inches of rain. Average high around 84F and low around 66F, with the sea about 79F. Bright, dry and still comfortable before the summer heat arrives. The one thing to plan around is not weather but crowds: spring break lands mid-month and both the town and the cruise piers get noticeably busier.
April has the fewest rainy days of any month, about 4.3 on average, with highs near 86F, lows near 68F and water around 80F. It is warm, dry and quieter than the February and March peak, which makes late April one of the best value windows of the year. Sargassum typically starts showing on the exposed east coast toward the end of the month, though the west-side beaches stay clear.
These are the wet months and the hurricane peak. September is the cloudiest month and averages the most rainy days at about 15.9; October brings the most total rainfall at around 5.6 inches. Temperatures stay warm, highs around 88F in September and 86F in October, with the sea at its warmest of the year. They are also comfortably the cheapest months to visit. Book them with travel insurance and a flexible itinerary, or not at all.
Atlantic hurricane season officially runs June 1 through November 30, with the genuine risk concentrated in September and October. A direct hit in any given year is uncommon, but a storm anywhere in the region can cancel the Playa del Carmen ferry and ground the dive boats for a few days even under clear skies overhead. That indirect disruption is far more likely than a storm actually reaching you.
It ranges from about 79F at the late-winter low to about 85F at the late-summer peak, so it is swimmable every month of the year. Snorkelers need no exposure protection at all. Most divers are fine in a 3mm shorty or a skin year round, with a full 3mm being plenty in the coolest months. Visibility generally runs 80 to 100 feet or better all year, and is clearest from roughly December through May.
Usually not. From June through August the normal pattern is a bright morning, clouds building after lunch, then a hard downpour lasting maybe half an hour before the sky clears again. You lose an hour, not a day, and the rain is warm. September and October are the exception, when systems get larger and slower and a genuinely washed-out day becomes possible.
Weather against crowds, price and cruise traffic, so you pick a window instead of just a temperature.
ExploreWhich beaches stay clear, why the west coast wins, and the months the mainland struggles.
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What a day really costs by travel style, and how the cheap months compare to peak season.
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Reefs, ruins, beach clubs and port-day picks, sorted by who you actually are.
ExploreEvery month here is warm and swimmable. The choice is really about rain odds, hurricane risk, crowds and price, and those four move together. Line them up and book the trade you are happiest making.