The climate of Cozumel is tropical, with a muggy, rainy season from May to October and a cooler, relatively dry season from November to April. However, also in the latter season, rainfall may occur, in addition to wind and cloudiness, especially in December and January.
The island is located off the east coast of Yucatan. From the main city, San Miguel, you can see Playa del Carmen.
Winter is typically warm, but sometimes, from mid-November to mid-March, there can be cool and windy days, when the wind from the United States (el norte) blows. The temperature can drop to 10/12 °C (50/54 °F) at night, and it can remain around 20/22 °C (68/72 °F) during the day.
From June to November (but with a higher probability from August to October), there is the risk of hurricanes.
The average temperature of the coldest month (January) is of 23.2 °C (74 °F), that of the warmest month (August) is of 28.2 °C (83 °F). Here are the average temperatures.

Precipitation amounts to 1,490 millimeters (58.7 inches) per year: it is therefore quite abundant. It ranges from 30 mm (1.2 in) in the driest month (March) to 245 mm (9.6 in) in the wettest (October). Here is the average precipitation.

On average, there are around 2,510 sunshine hours per year. Here are the average sunshine hours per day.

The sea temperature ranges between 26 °C (79 °F) and 29 °C (84 °F). It is therefore high enough for swimming all year round. Here are the average sea temperatures.

Best Time

The best time to visit Cozumel runs from mid-March to late May, which is a warm period, relatively dry and with frequent sunshine. In May, the first thunderstorms can occur. In winter, from December to mid-March, you may very well find a warm and sunny week, but at other times, there may be a few days with wind, clouds and some rain. Until March, when the Norte can blow, it can be cool at night, so it's better to bring a sweatshirt for the evening.