Nairobi Weather in September
Kenya · Subtropical Highlands climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Nairobi sees average temperatures ranging from a low of 13.3°C (55.9°F) to a high of 25.1°C (77.2°F), with a mean of 18.6°C (65.5°F). Compared to the annual average of 18.9°C (66.0°F), this month is 0.3°C cooler than the yearly norm. Precipitation averages 33.8mm, making it approximately 38.0mm drier than the monthly average of 72.0mm. The city receives an average of 9.8 hours of sunshine per day during September, with relative humidity averaging 67.3%. Wind speeds reach an average maximum of 12.2 km/h. For travelers, this month offers a temperature experience in Nairobi, with drier-than-average conditions compared to the rest of the year.
If you're planning outdoor activities in Nairobi, the altitude (1,795m) is your friend — 25°C feels like 22°C, UV is the trade-off. I ran Karura Forest in August at 8am: 18°C, perfect, but UV already at 6 by 9am. The long rains (April-May) turn trails muddy; pack waterproof shoes. The short rains (October-November) are briefer and the green season is gorgeous for hiking. June-September is the outdoor sweet spot: dry, 20-22°C, low humidity. Nairobi National Park game drives are best June-October. Always bring sun protection — equatorial UV is no joke even on cloudy afternoons.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 17.5°C (63.5°F) | 18.6°C (65.5°F) | 19.9°C (67.8°F) |
| Rainfall | 29.3mm | 33.8mm | 46.1mm |
| Sunshine | 8.2 hrs | 9.8 hrs | 10.6 hrs |
| Humidity | 69.0% | 67.3% | 63.1% |
| Wind | 12.5 km/h | 12.2 km/h | 14.3 km/h |
| Rainy Days | 17.8 | 18.8 | 21.6 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Nairobi in September, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Nairobi in September?
The average temperature in Nairobi during September ranges from 13.3°C (55.9°F) to 25.1°C (77.2°F), with a mean of 18.6°C (65.5°F).
How much does it rain in Nairobi in September?
Nairobi receives an average of 33.8mm of precipitation in September, spread across approximately 18.8 rainy days.
What should I pack for Nairobi in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is September a good time to visit Nairobi?
September is a good time to visit Nairobi, with comfortable temperatures and manageable rainfall.
Other Months for Nairobi
Cities with Similar September Climate (Subtropical Highlands)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: -1.29°, 36.82°. Timezone: Africa/Nairobi. Last updated: 2026-07-30.