Kenya weather by month

In Nairobi, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around November 23 and lasts for 4.7 months, ending around April 15. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 64% of the time on average.

The cloudier part of the year begins around April 16 and lasts for 4.9 months, ending around September 12. The cloudiest month is July, when it is overcast or mostly cloudy 88% of the time.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Nairobi is typically calm, near 9 km/h, and varies little with the seasons.

The windier part of the year lasts 6.8 months, from around Sep 17 to Apr 12. The windiest month is March, averaging about 11 km/h (calm).

The calmer part of the year runs from around Apr 13 to Sep 16, with June the calmest month at about 7 km/h.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Nairobi receives about 5.5 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.1 and 6.8 kWh/m².

The brighter stretch of the year lasts 4.5 months, from around Dec 1 to Apr 16. The brightest month is February, averaging about 6.8 kWh/m² (intense).

The dimmest month is July, down near 4.1 kWh/m² — roughly 39% less than the February peak.