September weather forecast
Libreville, Gabon

As the Libreville steps into September, it encounters a marked increase in rainfall compared to the preceding dry months. Despite the rise in precipitation, it falls well short of the earlier months of the year. Wind speeds decrease compared to August with gear down to an annual low. The sea temperature continues on its upward trajectory from August, with the oceanic environment becoming ever more inviting. Humidity levels return to a higher level, reinstating the typical tropical feel to the city.

Temperature

As August transitions into September, Libreville records an average high-temperature of a still moderately hot 27.8°C (82°F), showing a gentle shift from the preceding month. September nights in Libreville, Gabon, witness a mild cool down to an average low of 23.5°C (74.3°F).

Heat index

Throughout September, the heat index is calculated to be a tropical 32°C (89.6°F). With unrelenting exposure and activity, one might experience exhaustion, leading to potential heat cramps.
The heat index's values are generally associated with conditions in shade and light breezes. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'real feel' or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. One's perception of weather can be shaped by other factors, involving metabolic differences, pregnancy, and physical exertion. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.

Humidity

In Libreville, the average relative humidity in September is 83%.

Rainfall

In Libreville, during September, the rain falls for 17.7 days and regularly aggregates up to 76mm (2.99") of precipitation. In Libreville, during the entire year, the rain falls for 274.1 days and collects up to 1477mm (58.15") of precipitation.

Sea temperature

In September, the average sea temperature is 25.7°C (78.3°F).
Note: For any water activity, the surface water temperatures in the range of 25°C (77°F) to 29°C (84.2°F) are deemed excellent and incredibly pleasant for longer durations.

Daylight

The average length of the day in September is 12h and 7min.
On the first day of the month, sunrise is at 06:18 and sunset at 18:25. On the last day of September, in Libreville, sunrise is at 06:08 and sunset at 18:15 WAT.

Sunshine

With an average of 5.1h of sunshine, September has the least sunshine of the year.

UV index

The months with the lowest UV index are June through October, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index of 6 in September converts into the following recommendations:
Use protective steps and abide by sun safety guidelines. Safeguarding against skin and eye harm is necessary. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Beware! Reflecting off water and sand, UV rays are much stronger.