Brazil weather by month

In Sao Paulo, 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 March 29 and lasts for 5.7 months, ending around September 19. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 62% of the time on average.

The cloudier part of the year begins around September 20 and lasts for 6.2 months, ending around March 28. The cloudiest month is January, when it is overcast or mostly cloudy 75% 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.

Wind in Sao Paulo is steady company: average speeds sit near 10 km/h — calm — in every month of the year, with no meaningful windy or calm season.

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.

Sao Paulo receives about 4.7 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.3 and 5.7 kWh/m².

The brighter stretch of the year lasts 7.0 months, from around Aug 29 to Mar 30. The brightest month is November, averaging about 5.5 kWh/m² (bright).

The dimmest month is June, down near 3.4 kWh/m² — roughly 39% less than the November peak.