September weather forecastNiamey, Niger

September
Weather in September
As the wet season draws to a close, September in Niamey witnesses a gradual return of the hot and arid conditions typical of this Sahelian landscape. A fair decrease in rainfall from August's peak is observed, dropping more than a threefold to 9mm (0.35"). Winds blowing at an average of 11.6km/h (7.2mph) help to keep the temperature under control. Breaks in the cloud appear more frequently, signalling the imminent end of the wet season. Steady daylight indicates consistency in tropical weather, with high visibility dissuading the onset of any fog-like conditions.Temperature
The advent of September in Niamey reveals an average high-temperature of a torrid 36.7°C (98.1°F), showing minimal difference from the prior month. Niamey registers a consistent average low-temperature of 26.9°C (80.4°F) during September.Heat index
September's mean heat index is calculated to be a blistering 44°C (111.2°F). Alert: Heat cramps and heat exhaustion are likely to occur. Prolonged exertion can lead to heatstroke.Heat index determinations are made taking into account the shade and light air movements. Exposure to the direct sun could elevate the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', quantifies the warmth felt when relative humidity is considered. One's perception of temperature is subjective, varying based on their activity and individual heat perception, influenced by factors like wind, clothing, and metabolic variations. Understand that direct sun rays can influence the weather's impact, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Children frequently underestimate the importance of resting and drinking fluids. Thirst is a symptom of advanced dehydration - hence the need to hydrate regularly, especially during protracted physical exercises.
Perspiring is a crucial mechanism for the human body, allowing it to release excessive warmth through evaporating sweat. When relative humidity is on the rise, it curtails evaporation, thereby reducing the heat elimination from the body and causing the feeling of being excessively hot. With body temperatures on the rise, inefficient heat shedding can lead to dehydration and its associated complications.
Humidity
In Niamey, the average relative humidity in September is 48%.Rainfall
In Niamey, Niger, in September, it is raining for 4.2 days, with typically 9mm (0.35") of accumulated precipitation. Throughout the year, in Niamey, Niger, there are 34.7 rainfall days, and 99mm (3.9") of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 12min.On the first day of September, sunrise is at 06:40 and sunset at 19:02. On the last day of the month, sunrise is at 06:40 and sunset at 18:41 WAT.
Sunshine
In Niamey, the average sunshine in September is 9.7h.UV index
In September, the average daily maximum UV index in Niamey is 8. A UV Index value of 8 to 10 symbolizes a very high threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index of 8 during September translates into these guidelines:
Be sure to take precautions. Without protection, skin might suffer damage quickly. 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 days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Niamey, Niger
- Average high temperature in September: 36.7°C
The warmest month (with the highest average high temperature) is April (42.2°C).
The months with the lowest average high temperature are January and December (33.5°C).
- Average low temperature in September: 26.9°C
The month with the highest average low temperature is May (30.4°C).
The coldest month (with the lowest average low temperature) is January (16.9°C).
Average pressure in September
Niamey, Niger
- Average pressure in September: 1010.5mbar
The month with the highest atmospheric pressure is January (1012.8mbar).
The month with the lowest atmospheric pressure is April (1007mbar).
Average wind speed in September
Niamey, Niger
- Average wind speed in September: 11.6km/h
The windiest months (with the highest average wind speed) are January, July and December (14.7km/h).
The calmest month (with the lowest average wind speed) is October (10.4km/h).
Average humidity in September
Niamey, Niger
- Average humidity in September: 48%
The month with the highest relative humidity is August (55%).
The month with the lowest relative humidity is March (12%).
Average rainfall in September
Niamey, Niger
- Average rainfall in September: 9mm
The wettest month (with the highest rainfall) is August (42mm).
The driest months (with the least rainfall) are January, November and December (0mm).
Average rainfall days in September
Niamey, Niger
- Average rainfall days in September: 4.2 days
The month with the highest number of rainy days is August (9.1 days).
The months with the least rainy days are January and November (0 days).
Average daylight in September /
Average sunshine in September
Niamey, Niger
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 12h and 54min).
The month with the shortest days is December (Average daylight: 11h and 18min).
- Average sunshine in September: 9h and 42min
The months with the most sunshine are February, March, June, November and December (Average sunshine: 9h and 54min).
The month with the least sunshine is August (Average sunshine: 8h and 48min).
Average sunshine days in September
Niamey, Niger
- Average sunshine days in September: 25.5 days
The month with the most sunshine days is January (31 days).
The month with the least sunshine days is August (21.1 days).
Average UV index in September
Niamey, Niger
- Average UV index in September: 8
The months with the highest UV index are April and May (UV index 9).
The month with the lowest UV index is December (UV index 6).
Average cloud cover in September
Niamey, Niger
- Average cloud cover in September: 17
The month with the most cloud cover is August (Cloud cover 30).
The months with the least cloud cover are November and December (Cloud cover 4).
Average visibility in September
Niamey, Niger
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).





