Canada weather by month

In Toronto, 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 28 and lasts for 5.6 months, ending around October 15. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 56% of the time on average.

The cloudier part of the year begins around October 16 and lasts for 6.4 months, ending around April 27. The cloudiest month is December, when it is overcast or mostly cloudy 79% 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 Toronto is typically light breeze, near 13 km/h, and varies moderately with the seasons.

The windier part of the year lasts 6.7 months, from around Oct 4 to Apr 24. The windiest month is January, averaging about 16 km/h (light breeze).

The calmer part of the year runs from around Apr 25 to Oct 3, with August the calmest month at about 11 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.

Toronto receives about 3.9 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 1.3 and 6.4 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 14 to Sep 20. The brightest month is June, averaging about 6.3 kWh/m² (intense).

The dimmest month is December, down near 1.3 kWh/m² — roughly 79% less than the June peak.