Eritrea weather by month

In Asmara, 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 September 4 and lasts for 3.9 months, ending around December 31. The clearest month is November, when the sky is clear, mostly clear, or partly cloudy 87% of the time on average.

The cloudier part of the year begins around June 21 and lasts for 2.5 months, ending around September 3. The cloudiest month is August, when it is overcast or mostly cloudy 49% 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 Asmara is typically calm, near 6 km/h, and varies little with the seasons.

The windier part of the year lasts 4.6 months, from around May 26 to Oct 13. The windiest month is July, averaging about 9 km/h (calm).

The calmer part of the year runs from around Oct 14 to May 25, with November the calmest month at about 5 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.

Asmara receives about 5.8 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 5.0 and 6.7 kWh/m².

The brighter stretch of the year lasts 4.2 months, from around Feb 22 to Jun 28. The brightest month is April, averaging about 6.7 kWh/m² (intense).

The dimmest month is December, down near 5.1 kWh/m² — roughly 24% less than the April peak.