Climate averages 1991–2020
Nairobi weather
in September.
A warm, fairly dry month: the 6th warmest and the 2nd driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Nairobi: daytime highs average 24.2°C and nights cool to about 13.2°C. By daytime temperature it is the 6th warmest of the 12 months.
Expect about 16 mm of rain on roughly 3 days, which makes September a fairly dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 06 min on an average September day.
The nearest other city in this atlas is Karuri (Kiambu County), Kenya (14 km away). In September its highs average 22.1°C, 2.1°C cooler than Nairobi, with 16 mm of rain.
Among the 37 cities listed in Kenya, Nairobi ranks 26th of 37 for the warmest September highs and joint 11th of 37 for the driest September (rainfall, lowest first). The mean September high of those 37 cities is 25.7°C; Nairobi is 1.5°C cooler than that mean.
From September to October, average highs rise by 0.8°C to 25.0°C, and monthly rainfall rises from 16 mm to 40 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Nairobi climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 25.6°C14.4°C | 14.4°C | 35 | 6.3 | 12.212 h |
| February | 26.8°C14.9°C | 14.9°C | 30 | 4.6 | 12.212 h |
| March | 26.5°C15.6°C | 15.6°C | 57 | 10.3 | 12.112 h |
| April | 24.4°C15.8°C | 15.8°C | 114 | 19.4 | 12.112 h |
| May | 23.2°C14.9°C | 14.9°C | 92 | 16.0 | 12.112 h |
| June | 22.2°C13.6°C | 13.6°C | 42 | 7.9 | 12.012 h |
| July | 21.7°C12.4°C | 12.4°C | 13 | 3.2 | 12.112 h |
| August | 22.3°C12.6°C | 12.6°C | 21 | 3.9 | 12.112 h |
| September, selected | 24.2°C13.2°C | 13.2°C | 16 | 3.3 | 12.112 h |
| October | 25.0°C14.5°C | 14.5°C | 40 | 9.3 | 12.112 h |
| November | 23.2°C14.8°C | 14.8°C | 83 | 17.6 | 12.212 h |
| December | 24.0°C14.4°C | 14.4°C | 47 | 10.2 | 12.212 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Karuri (Kiambu County), Kenya in SeptemberKenya · 14 kmHigh 22.1°C · Low 11.7°C · 16 mm rain
- Ongata Rongai in SeptemberKenya · 14 kmHigh 23.8°C · Low 13.2°C · 12 mm rain
- Kikuyu in SeptemberKenya · 18 kmHigh 21.9°C · Low 11.5°C · 16 mm rain
- Ngong in SeptemberKenya · 18 kmHigh 23.6°C · Low 12.5°C · 16 mm rain
- Mlolongo in SeptemberKenya · 19 kmHigh 24.3°C · Low 13.5°C · 11 mm rain
- Ruiru in SeptemberKenya · 22 kmHigh 24.3°C · Low 13.2°C · 9.5 mm rain
- Kitengela in SeptemberKenya · 27 kmHigh 24.5°C · Low 13.9°C · 11 mm rain
- Limuru in SeptemberKenya · 27 kmHigh 20.3°C · Low 9.8°C · 32 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Nairobi) is explained once on the Nairobi year overview and on the Sources, method and limits page.
Kikuyu, Karuri (Kiambu County), Kenya and Ngong lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.