Cozumel
Mexico
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Cozumel, Mexico

A small blue boat, palm trees, and clear blue waters on Chen Rio white sandy beach in Cozumel, Mexico, with a small island
A small blue boat, palm trees, and clear blue waters on Chen Rio white sandy beach in Cozumel, Mexico, with a small island
September, the first month of the autumn, in Cozumel, is still a hot month, with average temperature fluctuating between 23.6°C (74.5°F) and 31.9°C (89.4°F).

Temperature

In September, the average high-temperature is almost the same as in August - a still tropical 31.9°C (89.4°F). In Cozumel, Mexico, the average low-temperature is 23.6°C (74.5°F).

Heat index

The average heat index in September is estimated at a blazing hot 47.1°C (116.8°F). Be wary - heat exhaustion and heat cramps are highly anticipated. With continued activity, heatstroke is very likely.
Note that heat index values are valued for light wind and location in the shade. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'feels like', 'real feel', or 'apparent temperature', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Additional factors like activity, wind, differences in body mass, height, and shape, and clothing affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. With a lot of moisture in the air, the evaporation process is not as effective, and the body does not cool down as efficiently, creating a perception of overheating. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

The most humid month in Cozumel is September, with an average relative humidity of 87%.

Rainfall

In Cozumel, it is raining for 15.4 days, with typically 240.2mm (9.5") of accumulated precipitation. In Cozumel, during the entire year, the rain falls for 119.9 days and collects up to 1489.9mm (58.7") of precipitation.

Sea temperature

July through October, with an average sea temperature of 29°C (84.2°F), are months with the warmest seawater.
Note: For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.

Daylight

In Cozumel, the average length of the day in September is 12.2h.

Sunshine

September and November, with an average of 6.1h of sunshine, are months with the least sunshine in Cozumel, Mexico.

UV index

In Cozumel, the average daily maximum UV index in September is 11. A UV Index of 11, and more, symbolizes an extreme health hazard from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 11 transform into the following instructions:
Take all required precautions, as unprotected skin and eyes can burn in minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in September in Cozumel?

In September, the average high-temperature is 31.9°C (89.4°F), and the average low-temperature is 23.6°C (74.5°F). The average heat index (a.k.a. 'real feel', 'apparent temperature'), that combines both air temperature and relative humidity, in September is appraised at 47.1°C (116.8°F).

What is the most humid month in Cozumel?

The most humid month in Cozumel, Mexico, is September, with an average relative humidity of 87%.

What is the average humidity in September in Cozumel?

In Cozumel, the average relative humidity in September is 87%.

How much does it rain in Cozumel in September?

In Cozumel, Mexico, during September, the rain falls for 15.4 days and regularly aggregates up to 240.2mm (9.5") of precipitation.

What are the months with the warmest sea water in Cozumel?

July through October, with an average sea temperature of 29°C (84.2°F), are months with the warmest seawater in Cozumel, Mexico.

How warm is the water in September in Cozumel?

In Cozumel, Mexico, in September, the average water temperature is 29°C (84.2°F). For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

What is the average length of the day in September in Cozumel?

The average length of the day in September is 12.2h.

What is the month with the least sunshine in Cozumel?

Months with the least sunshine are September and November, with an average of 6.1h of sunshine.

How many hours of sunshine does Cozumel have in September?

In September, the average sunshine in Cozumel is 6.1h.

How high is the UV index in September in Cozumel?

In September, the average daily maximum UV index in Cozumel is 11. A UV Index value of 11, and more, symbolizes an extreme health threat from unprotected exposure to the UV radiation.
Average temperature in September - Cozumel, Mexico
  • Average high temperature in September: 31.9°C

The warmest month (with the highest average high temperature) is August (33°C).
Months with the lowest average high temperature are January and December (28.6°C).

  • Average low temperature in September: 23.6°C

The month with the highest average low temperature is June (23.8°C).
Coldest months (with the lowest average low temperature) are January and February (19.4°C).

Average humidity in September - Cozumel, Mexico
  • Average humidity in September: 87%

The month with the highest relative humidity is September (87%).
Months with the lowest relative humidity are March and April (79%).

Average rainfall in September - Cozumel, Mexico
  • Average rainfall in September: 240.2mm

The wettest month (with the highest rainfall) is October (242.5mm).
The driest month (with the lowest rainfall) is March (32.2mm).

Average rainfall days in September - Cozumel, Mexico
  • Average rainfall days in September: 15.4 days

The month with the highest number of rainy days is October (15.7 days).
The month with the lowest number of rainy days is April (3.7 days).

Average sea temperature in September - Cozumel, Mexico
  • Average sea temperature in September: 29°C

Best months for swimming (with the highest average sea temperature) are July, August, September and October (29°C).
Coldest months (with the lowest average sea temperature) are February and March (26°C).

Average daylight in September / Average sunshine in September - Cozumel, Mexico
  • Average daylight in September: 12.2h

The month with the longest days is June (Average daylight: 13.4h).
The month with shortest days is December (Average daylight: 10.9h).

  • Average sunshine in September: 6.1h

The month with most sunshine is April (Average sunshine: 8.6h).
Months with least sunshine are September and November (Average sunshine: 6.1).

Average UV index in September - Cozumel, Mexico
  • Average UV index in September: 11

Months with the highest UV index are April, May, June, July and August (UV index 12).
Months with the lowest UV index are January and December (UV index 7).