Peru weather by month

In Lima, 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 April 20 and lasts for 6.0 months, ending around October 18. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 82% of the time on average.

The cloudier part of the year begins around October 19 and lasts for 6.0 months, ending around April 19. The cloudiest month is February, when it is overcast or mostly cloudy 96% 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 Lima is typically calm, near 9 km/h, and varies little with the seasons.

The windier part of the year lasts 6.9 months, from around May 20 to Dec 16. The windiest month is September, averaging about 10 km/h (calm).

The calmer part of the year runs from around Dec 17 to May 19, with March 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.

Lima receives about 5.9 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.8 and 6.9 kWh/m².

The brighter stretch of the year lasts 6.0 months, from around Aug 27 to Feb 26. The brightest month is November, averaging about 6.8 kWh/m² (intense).

The dimmest month is June, down near 4.9 kWh/m² — roughly 29% less than the November peak.