Nairobi weather in September
In September, Nairobi has an average high of 28 °C82 °F and an average low of 13 °C55 °F, with about 20 mm0.8 in of precipitation. It is the 6th warmest month of the year and ranks 11th for precipitation.
How September compares with other months
Compared with August, September is 1.1 °C2.1 °F warmer on average. Compared with October, September is 0.5 °C0.9 °F cooler on average and drier by 33 mm1.3 in. Daylight lasts about 12.1 hours around the middle of the month. Average relative humidity is 59% and the average cloud amount 57%.
Is September a good time to visit Nairobi?
Yes — September is one of the most comfortable months to visit Nairobi by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in September
For Nairobi in September, pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
September in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Nairobi | 2882 | 1355 | 200.8 |
| Ruiru | 2882 | 1457 | 281.1 |
| Thika | 2882 | 1457 | 281.1 |
| Mwala | 2984 | 1457 | 190.7 |
| Karuri | 2883 | 1661 | 622.4 |
| Nakuru | 2576 | 1355 | 853.3 |
| Arusha | 2882 | 1355 | 170.7 |
| Moshi | 3188 | 1661 | 170.7 |
| Kisii | 2678 | 1559 | 1164.6 |
Nearby places that are more than 1 °C1.8 °F warmer in September: Mwala, Karuri and Moshi; cooler: Nakuru.
Other months in Nairobi
- January27 °C81 °F / 13 °C56 °F
- February29 °C83 °F / 14 °C57 °F
- March28 °C83 °F / 14 °C58 °F
- April26 °C79 °F / 14 °C58 °F
- May25 °C77 °F / 13 °C56 °F
- June25 °C77 °F / 12 °C54 °F
- July25 °C77 °F / 12 °C53 °F
- August26 °C79 °F / 12 °C53 °F
- September28 °C82 °F / 13 °C55 °F
- October28 °C82 °F / 13 °C56 °F
- November26 °C78 °F / 14 °C57 °F
- December26 °C78 °F / 14 °C57 °F
Frequently asked questions
How warm is Nairobi in September?
In September the average high in Nairobi is 28 °C (82 °F) and the average low is 13 °C (55 °F).
Does it rain a lot in Nairobi in September?
On average about 20 mm (0.8 in) of precipitation falls in September; it ranks 11th of the 12 months.
Is September the warmest month in Nairobi?
No. The warmest month in Nairobi is February, with an average high of 29 °C (83 °F). The coldest month is July, with an average low of 12 °C (53 °F).
How long is the day in Nairobi in September?
In the middle of September the day in Nairobi lasts about 12.1 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Nairobi in September?
The average relative humidity in September is about 59%. This is a long-term average for the whole day.
How cloudy is Nairobi in September?
On average about 57% of the sky is covered by cloud in September. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.