China weather by month

In Shanghai, 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 July 22 and lasts for 5.6 months, ending around January 8. The clearest month is October, when the sky is clear, mostly clear, or partly cloudy 56% of the time on average.

The cloudier part of the year begins around February 14 and lasts for 5.2 months, ending around July 21. The cloudiest month is June, when it is overcast or mostly cloudy 78% 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 Shanghai is steady company: average speeds sit near 13 km/h — light breeze — 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.

Shanghai receives about 4.0 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 2.5 and 5.7 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Mar 17 to Sep 21. The brightest month is July, averaging about 5.2 kWh/m² (bright).

The dimmest month is January, down near 2.6 kWh/m² — roughly 50% less than the July peak.