Tanzania weather by month

In Dar es Salaam, 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 May 20 and lasts for 6.6 months, ending around December 5. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 89% of the time on average.

The cloudier part of the year begins around December 6 and lasts for 5.4 months, ending around May 19. The cloudiest month is April, when it is overcast or mostly cloudy 61% 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 Dar es Salaam is typically light breeze, near 14 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.5 months, from around Apr 26 to Oct 9. The windiest month is July, averaging about 17 km/h (light breeze).

The calmer part of the year runs from around Feb 11 to Apr 25, with March the calmest month at about 10 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.

Dar es Salaam receives about 5.7 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.6 and 6.4 kWh/m².

The brighter stretch of the year lasts 6.7 months, from around Aug 30 to Mar 22. The brightest month is October, averaging about 6.4 kWh/m² (intense).

The dimmest month is May, down near 4.7 kWh/m² — roughly 27% less than the October peak.