September Weather in Santo Antonio, Sao Tome and Principe

Last updated: August 31, 2025

In September, the average temperature in Santo Antonio, Sao Tome and Principe hovers around 26°C (78°F), with a minimum of 24°C (76°F) and a maximum reaching 27°C (81°F). Expect significant rainfall, with 259 mm (10.2 in) of precipitation spread over 24 days. The air is quite humid, showcasing an average humidity of 86%.

September Temperature in Santo Antonio

In September in Santo Antonio, the average temperature is 26°C (78°F). Maximums can reach 27°C (81°F), and minimums can be as low as 24°C (76°F). This pleasant climate makes Santo Antonio an ideal destination for travelers looking to enjoy warm weather and outdoor activities.

September Weather in Santo Antonio: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Santo Antonio, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santo Antonio, September typically has an average temperature of 26°C (78°F), with highs reaching up to 27°C (81°F) and lows dropping to around 24°C (76°F).

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

September Precipitation in Santo Antonio

In Santo Antonio in September, the precipitation amount is 259 mm (10.2 in) spread over a duration of 24 days.

September Precipitation Trends in Santo Antonio

The chart displays monthly precipitation patterns in Santo Antonio, 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 Santo Antonio, September typically receives around 259 mm (10.2 inches) of precipitation spread over approximately 24 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 Santo Antonio

In Santo Antonio in September, humidity is 86%. With an average temperature of 26°C (78°F), this humidity feels like an overwhelming blanket that clings to your skin, making any outdoor activity feel more strenuous and causing you to seek shade and refreshment more often during your travels.

September Average Humidity in Santo Antonio

This chart illustrates the average monthly humidity levels in Santo Antonio, 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 Santo Antonio is approximately 86%, 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 Santo Antonio

In Santo Antonio in September, the maximum UV index reaches 13, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's crucial to take protective measures. For detailed information, you can check the Hourly UV Index in Santo Antonio.

Maximum UV Index Levels in Santo Antonio for September

The chart shows the monthly maximum UV Index (UVI) for Santo Antonio 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 Santo Antonio typically reaches 13, which falls under the extreme exposure category.

Data source: Santo Antonio 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 Santo Antonio Compares to Other Months

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

This table compares monthly weather conditions in Santo Antonio, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	27°C (81°F)	101 mm (4.0 inches)	75%	extreme
February Weather	28°C (82°F)	96 mm (3.8 inches)	75%	extreme
March Weather	28°C (82°F)	159 mm (6.2 inches)	73%	extreme
April Weather	28°C (82°F)	194 mm (7.6 inches)	74%	extreme
May Weather	27°C (81°F)	212 mm (8.4 inches)	75%	extreme
June Weather	26°C (80°F)	156 mm (6.2 inches)	76%	extreme
July Weather	25°C (78°F)	111 mm (4.4 inches)	76%	very high
August Weather	25°C (78°F)	111 mm (4.4 inches)	83%	extreme
September Weather	26°C (78°F)	259 mm (10.2 inches)	86%	extreme
October Weather	26°C (79°F)	286 mm (11.2 inches)	85%	extreme
November Weather	26°C (80°F)	261 mm (10.3 inches)	81%	extreme
December Weather	27°C (80°F)	172 mm (6.8 inches)	76%	extreme