Sierra Leone weather by month

In Freetown, 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 October 30 and lasts for 6.1 months, ending around May 2. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 78% of the time on average.

The cloudier part of the year begins around May 3 and lasts for 5.9 months, ending around October 29. The cloudiest month is August, when it is overcast or mostly cloudy 91% 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 Freetown is typically light breeze, near 14 km/h, and varies a lot with the seasons.

The windier part of the year lasts 2.9 months, from around Jun 23 to Sep 19. The windiest month is August, averaging about 19 km/h (light breeze).

The calmer part of the year runs from around Sep 20 to Jan 24, with November the calmest month at about 9 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.

Freetown receives about 5.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.8 and 6.3 kWh/m².

The brighter stretch of the year lasts 5.3 months, from around Dec 11 to May 19. The brightest month is March, averaging about 6.3 kWh/m² (intense).

The dimmest month is August, down near 3.9 kWh/m² — roughly 37% less than the March peak.