Thornhill Weather & Climate: Best Time to Visit

In Thornhill, temperatures differ significantly between summer and winter months. On average, daytime temperatures range from a pleasant 19°C (66°F) in July to a chilly 7°C (45°F) in January.

Nighttime temperatures range from 11°C (52°F) in July to 1°C (34°F) in January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Thornhill experiences significant rain/snowfall throughout the year, averaging 1369 mm (54 in) of precipitation annually. The wettest period in Thornhill occurs in December, which receives around 134 mm (5.3 in) of precipitation. During the driest month, April, Thornhill experiences moderate rainfall, totaling 92 mm (3.6 in). The consistent precipitation levels throughout the year contribute to a relatively stable climate. For more details, please visit our Thornhill Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

In Thornhill, summer days are longer and more sunny, with daily sunshine hours peaking at 5.4 hours in May. As the darker season arrives, the brightness of the sun becomes less. January sees a soft sun for only 1.3 hours per average day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The city experiences its highest humidity in December, reaching 90%. In May, the humidity drops to its lowest level at 70%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year