WEATHER · CLIMATE NORMALS · 1991–2020
Nairobi Climate — Averages by Month
What the weather in Nairobi, KEaverages across a standard 30-year period. Each month's figure is the 1991–2020 mean temperature and total rainfall from the ERA5 reanalysis — the long-run normal a place settles around, not a forecast for any particular day.
Month-by-month normals
| Month | Avg temperature | Avg rainfall |
|---|---|---|
| January | 19.7 °C | 39.6 mm |
| February | 20.5 °C | 33.0 mm |
| March | 20.7 °C · warmest | 63.8 mm |
| April | 19.8 °C | 125.7 mm · wettest |
| May | 18.8 °C | 101.6 mm |
| June | 17.8 °C | 49.8 mm |
| July | 16.9 °C · coldest | 20.2 mm |
| August | 17.2 °C | 28.2 mm |
| September | 18.4 °C | 22.0 mm |
| October | 19.4 °C | 48.7 mm |
| November | 18.8 °C | 93.6 mm |
| December | 19.0 °C | 54.2 mm |
How to read these numbers
These are reanalysis normals, not readings from a single weather station. They come from the ERA5 0.25° (~25 km) global reanalysis grid, sampled at the grid cell nearest Nairobi — centred at 1.25°S, 36.75°E. A reanalysis blends observations with a physics model onto an even grid, so a coastal or mountain city's cell can read a little cooler, warmer, wetter or drier than the city centre itself. The month-to-month shape — when it's hot, when it rains — is what these normals capture best.
“Normal” means the 1991–2020 average, the current World Meteorological Organization standard period. A normal is what a place tends toward over decades — any single day, month or year can and will depart from it.