Bissau
Guinea-Bissau
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Bissau, Guinea-Bissau

Trees along the golden sandy shores of Bijagos Islands in Bissau, Guinea Bissau in West Africa, with ships sailing on the calm waters under clear blue skies
Trees along the golden sandy shores of Bijagos Islands in Bissau, Guinea Bissau in West Africa, with ships sailing on the calm waters under clear blue skies
The first month of the autumn, September, is still a tropical month in Bissau, Guinea-Bissau, with average temperature fluctuating between 22.8°C (73°F) and 30°C (86°F).

Temperature

In Bissau, the average high-temperature remains equal as in August - a still tropical 30°C (86°F). In September, the average low-temperature is 22.8°C (73°F).

Rainfall

In September, in Bissau, the rain falls for 19 days. Throughout September, 434.9mm (17.1") of precipitation is accumulated. Throughout the year, there are 86 rainfall days, and 2022.8mm (79.6") of precipitation is accumulated.

Sea temperature

In September, the average sea temperature is 28.3°C (82.9°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

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

Sunshine

The average sunshine in September is 6h.

UV index

Months with the highest UV index are February through September, with an average maximum UV index of 12. A UV Index reading of 11, and higher, represents an ultimate health vulnerability from the exposure to the Sun's UV radiation for the ordinary person.
Note: The daily maximum UV index of 12 in September interpret into the following advice:
Practice all-important precautions. Light skin people may get burned in less than 5 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. 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. 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 Bissau?

The average high-temperature, in September, in Bissau, is 30°C (86°F), while the average low-temperature is 22.8°C (73°F).

How many days does it rain in September in Bissau?

In Bissau, Guinea-Bissau, in September, during 19 rainfall days, 434.9mm (17.1") of precipitation is typically accumulated.

How warm is the water in September in Bissau?

In September, the average sea temperature in Bissau is 28.3°C (82.9°F). Water temperature between 25°C (77°F) and 29°C (84.2°F) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

How many hours of daylight does Bissau have in September?

The average length of the day in September in Bissau, Guinea-Bissau, is 12.2h.

How long on average sun shines in September in Bissau?

In September, the average sunshine in Bissau, Guinea-Bissau, is 6h.

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

Months with the highest UV index in Bissau, Guinea-Bissau, are February through September, with an average maximum UV index of 12.

What is the UV index intensity in September in Bissau?

In Bissau, the average daily maximum UV index in September is 12. A UV Index reading of 11, and higher, represents an ultimate hazard to health from unprotected exposure to the UV radiation.
Average temperature in September - Bissau, Guinea-Bissau
  • Average high temperature in September: 30°C

The warmest month (with the highest average high temperature) is March (33.9°C).
The month with the lowest average high temperature is July (29.4°C).

  • Average low temperature in September: 22.8°C

Months with the highest average low temperature are June, July, August, September and October (22.8°C).
The coldest month (with the lowest average low temperature) is January (17.8°C).

Average rainfall in September - Bissau, Guinea-Bissau
  • Average rainfall in September: 434.9mm

The wettest month (with the highest rainfall) is August (682.5mm).
Driest months (with the lowest rainfall) are January and March (0.5mm).

Average rainfall days in September - Bissau, Guinea-Bissau
  • Average rainfall days in September: 19 days

The month with the highest number of rainy days is August (22 days).
Months with the lowest number of rainy days are January, February and March (0 days).

Average sea temperature in September - Bissau, Guinea-Bissau
  • Average sea temperature in September: 28.3°C

Best months for swimming (with the highest average sea temperature) are October and November (28.8°C).
The coldest month (with the lowest average sea temperature) is February (24.8°C).

Average daylight in September / Average sunshine in September - Bissau, Guinea-Bissau
  • Average daylight in September: 12.2h

The month with the longest days is June (Average daylight: 12.8h).
The month with shortest days is December (Average daylight: 11.4h).

  • Average sunshine in September: 6h

Months with most sunshine are March and April (Average sunshine: 9h).
The month with least sunshine is August (Average sunshine: 5h).

Average UV index in September - Bissau, Guinea-Bissau
  • Average UV index in September: 12

Months with the highest UV index are February, March, April, May, June, July, August and September (UV index 12).
The month with the lowest UV index is December (UV index 9).