India weather by month

In Mumbai, 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 10 and lasts for 7.8 months, ending around June 2. The clearest month is April, when the sky is clear, mostly clear, or partly cloudy 96% of the time on average.

The cloudier part of the year begins around June 3 and lasts for 4.2 months, ending around October 9. The cloudiest month is July, when it is overcast or mostly cloudy 95% 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 Mumbai is typically calm, near 11 km/h, and varies a lot with the seasons.

The windier part of the year lasts 3.8 months, from around May 16 to Sep 9. The windiest month is July, averaging about 18 km/h (light breeze).

The calmer part of the year runs from around Sep 10 to May 15, with October the calmest month at about 8 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.

Mumbai receives about 5.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.3 and 7.2 kWh/m².

The brighter stretch of the year lasts 4.7 months, from around Jan 16 to Jun 6. The brightest month is April, averaging about 7.1 kWh/m² (intense).

The dimmest month is July, down near 3.4 kWh/m² — roughly 52% less than the April peak.