September weather forecastLibreville, Gabon
September
Weather in September
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.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Libreville, Gabon
- Average high temperature in September: 27.8°C
The warmest month (with the highest average high temperature) is March (30.1°C).
The month with the lowest average high temperature is July (26.5°C).
- Average low temperature in September: 23.5°C
The month with the highest average low temperature is March (25.3°C).
The coldest month (with the lowest average low temperature) is July (22.5°C).
Average pressure in September
Libreville, Gabon
- Average pressure in September: 1012.9mbar
The month with the highest atmospheric pressure is July (1014mbar).
The months with the lowest atmospheric pressure are February and March (1010mbar).
Average wind speed in September
Libreville, Gabon
- Average wind speed in September: 12.5km/h
The windiest month (with the highest average wind speed) is August (13.4km/h).
The calmest month (with the lowest average wind speed) is April (8.2km/h).
Average humidity in September
Libreville, Gabon
- Average humidity in September: 83%
The month with the highest relative humidity is November (86%).
The months with the lowest relative humidity are January, February, March and August (81%).
Average rainfall in September
Libreville, Gabon
- Average rainfall in September: 76mm
The wettest month (with the highest rainfall) is November (226mm).
The driest month (with the least rainfall) is July (9mm).
Average rainfall days in September
Libreville, Gabon
- Average rainfall days in September: 17.7 days
The month with the highest number of rainy days is January (30 days).
The month with the least rainy days is July (8.3 days).
Average sea temperature in September
Libreville, Gabon
- Average sea temperature in September: 25.7°C
The best month for swimming (with the highest average sea temperature) is March (29.3°C).
The coldest month (with the lowest average sea temperature) is July (24.7°C).
Average daylight in September /
Average sunshine in September
Libreville, Gabon
- Average daylight in September: 12h and 6min
The month with the longest days is June (Average daylight: 12h and 6min).
The month with the shortest days is December (Average daylight: 12h and 6min).
- Average sunshine in September: 5h and 6min
The month with the most sunshine is February (Average sunshine: 8h and 18min).
The month with the least sunshine is September (Average sunshine: 5h and 6min).
Average sunshine days in September
Libreville, Gabon
- Average sunshine days in September: 9.9 days
The month with the most sunshine days is July (20.7 days).
The month with the least sunshine days is January (0.6 days).
Average UV index in September
Libreville, Gabon
- Average UV index in September: 6
The months with the highest UV index are January, February, March, April, May, November and December (UV index 7).
The months with the lowest UV index are June, July, August, September and October (UV index 6).
Average cloud cover in September
Libreville, Gabon
- Average cloud cover in September: 74
The month with the most cloud cover is September (Cloud cover 74).
The month with the least cloud cover is February (Cloud cover 42).
Average visibility in September
Libreville, Gabon
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, June, July, August and September (10km).
The months with the lowest visibility are April, May, October, November and December (9km).
