September Weather in Bissau, Guinea-Bissau

Last updated: August 23, 2025

In September, the average temperature in Bissau, Guinea-Bissau hovers around a pleasant 27°C (81°F). Expect the mercury to dip to a minimum of 23°C (73°F) and rise as high as 34°C (94°F). This month sees about 369 mm (14.5 in) of precipitation spread over 26 days, contributing to an average humidity of 84%. Perfect for enjoying those warm, tropical vibes!

September Temperature in Bissau

In September in Bissau, the average temperature is 27°C (81°F). The maximum can reach 34°C (94°F) and the minimum can be as low as 23°C (73°F). This pleasant climate makes it an ideal time for travel, offering warm days perfect for exploring and enjoying outdoor activities.

September Weather in Bissau: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Bissau, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Bissau, September typically has an average temperature of 27°C (81°F), with highs reaching up to 34°C (94°F) and lows dropping to around 23°C (73°F).

Data source: Temperature data for Bissau generated using information from the Copernicus Climate Change Service.

September Precipitation in Bissau

In Bissau in September, the precipitation amount is 369 mm (14.5 in) over a span of 26 days.

September Precipitation Trends in Bissau

The chart displays monthly precipitation patterns in Bissau, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Bissau, September typically receives around 369 mm (14.5 inches) of precipitation spread over approximately 26 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in Bissau

In Bissau in September humidity is 84%. With an average temperature of 27°C (81°F), this humidity feels like walking through a warm, moist blanket, making travel uncomfortable and sticky, as every step seems to weigh you down with the heavy air.

September Average Humidity in Bissau

This chart illustrates the average monthly humidity levels in Bissau, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Bissau is approximately 84%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bissau

In Bissau in September, the maximum UV index is 14, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, so it's crucial to take precautions. For the detailed hourly UV index in Bissau, you can check here.

Maximum UV Index Levels in Bissau for September

The chart shows the monthly maximum UV Index (UVI) for Bissau in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Bissau typically reaches 14, which falls under the extreme exposure category.

Data source: Bissau September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How September Weather in Bissau Compares to Other Months

Weather in Bissau varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Bissau, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Bissau, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	26°C (80°F)	0 mm (0.0 inches)	57%	very high
February Weather	27°C (82°F)	0 mm (0.0 inches)	64%	very high
March Weather	28°C (83°F)	0 mm (0.0 inches)	64%	extreme
April Weather	29°C (84°F)	0 mm (0.0 inches)	73%	extreme
May Weather	28°C (84°F)	1 mm (0.1 inches)	76%	extreme
June Weather	28°C (84°F)	52 mm (2.0 inches)	80%	extreme
July Weather	27°C (81°F)	453 mm (17.8 inches)	81%	extreme
August Weather	27°C (80°F)	539 mm (21.2 inches)	86%	extreme
September Weather	27°C (81°F)	369 mm (14.5 inches)	84%	extreme
October Weather	28°C (83°F)	134 mm (5.3 inches)	80%	extreme
November Weather	29°C (84°F)	24 mm (0.9 inches)	73%	very high
December Weather	27°C (81°F)	0 mm (0.0 inches)	65%	very high