September weather forecast and climate
Cotonou, Benin

The first month of the autumn, September, is still a warm month in Cotonou, Benin, with average temperature varying between 28.4°C (83.1°F) and 23.6°C (74.5°F).

Temperature

In September, the average high-temperature is relatively the same as in August - a still warm 28.4°C (83.1°F). In Cotonou, in September, the average low-temperature is 23.6°C (74.5°F).

Heat index

In September, the average heat index is estimated at a hot 33.5°C (92.3°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'felt air temperature', 'feels like', or 'real feel', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, clothing, metabolic differences), and activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

In Cotonou, the average relative humidity is 82%.

Rainfall

In September, in Cotonou, the rain falls for 8 days. Throughout September, 99mm (3.9") of precipitation is accumulated. Throughout the year, in Cotonou, there are 75 rainfall days, and 1308.3mm (51.51") of precipitation is accumulated.

Sea temperature

In Cotonou, the average seawater temperature is 26°C (78.8°F).
Note: 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.

Daylight

The average length of the day in Cotonou, Benin, is 12.2h.

Sunshine

The average sunshine in Cotonou is 5.5h.

UV index

February through May, August through October, with an average maximum UV index of 12, are months with the highest UV index in Cotonou. A UV Index estimate of 11, and higher, represents an extreme threat to health from unsafe exposure to the UV radiation for average individuals.
Note: The average daily UV index of 12 transform into the following instructions:
Practice all essential precautions. Protection against sun damage is crucial. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. 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. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.

What is the temperature in September in Cotonou?

In Cotonou, Benin, in September, the average high-temperature is 28.4°C (83.1°F), and the average low-temperature is 23.6°C (74.5°F). In September, the average heat index (a.k.a. 'felt air temperature', 'real feel'), that takes the relative humidity and factores it into the air temperature reading, is appraised at 33.5°C (92.3°F).

What is the average humidity in September in Cotonou?

In September, the average relative humidity in Cotonou, Benin, is 82%.

How many days does it rain in September in Cotonou?

In Cotonou, Benin, in September, it is raining for 8 days, with typically 99mm (3.9") of accumulated precipitation.

What is the sea water temperature in September in Cotonou?

In Cotonou, the average seawater temperature in September is 26°C (78.8°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.

How many hours of daylight does Cotonou have in September?

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

How many hours of sunshine does Cotonou have in September?

The average sunshine in September in Cotonou, Benin, is 5.5h.

What are the months with the highest UV index in Cotonou?

Months with the highest UV index in Cotonou are February through May, August through October, with an average maximum UV index of 12.

What is the UV index intensity in September in Cotonou?

In September, the average daily maximum UV index in Cotonou, Benin, is 12. A UV Index value of 11, and more, symbolizes an ultimate hazard to health from unsafe exposure to the Sun's UV rays.
Average temperature in September - Cotonou, Benin
  • Average high temperature in September: 28.4°C

The warmest month (with the highest average high temperature) is March (31.9°C).
The month with the lowest average high temperature is August (27.8°C).

  • Average low temperature in September: 23.6°C

The month with the highest average low temperature is March (25.9°C).
The coldest month (with the lowest average low temperature) is August (23.4°C).

Average humidity in September - Cotonou, Benin
  • Average humidity in September: 82%

The month with the highest relative humidity is June (84%).
The month with the lowest relative humidity is April (76.5%).

Average rainfall in September - Cotonou, Benin
  • Average rainfall in September: 99mm

The wettest month (with the highest rainfall) is June (356mm).
The driest month (with the least rainfall) is January (9.2mm).

Average rainfall days in September - Cotonou, Benin
  • Average rainfall days in September: 8 days

The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is January (1 days).

Average sea temperature in September - Cotonou, Benin
  • Average sea temperature in September: 26°C

The best months for swimming (with the highest average sea temperature) are March, April, May and November (29°C).
The coldest month (with the lowest average sea temperature) is August (25°C).

Average daylight in September / Average sunshine in September - Cotonou, Benin
  • Average daylight in September: 12.2h

Months with the longest days are June and July (Average daylight: 12.5h).
Months with the shortest days are January, November and December (Average daylight: 11.8h).

  • Average sunshine in September: 5.5h

The month with the most sunshine is November (Average sunshine: 8.1h).
The month with the least sunshine is July (Average sunshine: 4.4h).

Average UV index in September - Cotonou, Benin
  • Average UV index in September: 12

Months with the highest UV index are February, March, April, May, August, September and October (UV index 12).
The month with the lowest UV index is December (UV index 10).