Alliston (ON) Weather & Climate: Best Time to Visit

Temperatures in Alliston, Ontario, Canada, vary greatly throughout the year. July is the hottest month at 27°C (81°F), while January is the coldest at -1°C (30°F).

Annual rain/snowfall is moderate at around 919 mm (36 in), with June being the wettest month. Sunshine peaks in July, when the city sees around 9.8 hours of sunshine per day.

Monthly Temperature in Alliston

The climate in Alliston is known for significant temperature differences throughout the year, making the weather dynamic. Average daytime temperatures reach a comfortable 27°C (81°F) in July. In January, the coolest month of the year, temperatures drop to a very cold -1°C (30°F).

At night, temperatures range from around 15°C (59°F) in July to -11°C (12°F) in January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Rainfall in Alliston

Generally, Alliston receives mid-range precipitation levels, with 919 mm (36 in) annually. Despite minor fluctuations, Alliston enjoys fairly consistent precipitation throughout the year. In June, you can expect around 94 mm (3.7 in) of precipitation, while in February, Alliston receives about 60 mm (2.4 in). For more details, please visit our Alliston Precipitation page.

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

The average number of days each month with precipitation

Sunshine Hours in Alliston

Alliston can be enjoyed more throughout the sunniest month of July under a blue sky, with approximately 9.8 hours of sunshine daily. In contrast, the city experiences much darker days in January, with only 2.6 hours of sunlight per day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Data from: Mississauga, Canada (65 KM, 40 Miles).

Daily hours of sunshine

Data from: Mississauga, Canada (65 KM, 40 Miles).

Daily percentage of sunshine

Data from: Mississauga, Canada (65 KM, 40 Miles).

Humidity in Alliston by Month

The relative humidity is high throughout the year in Alliston.

The city experiences its highest humidity in January, reaching 72%. In May, the humidity drops to its lowest level at 53%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year

Data from: Mississauga, Canada (65 KM, 40 Miles).

Alliston (ON) 3-Day Forecast

10-Day Forecast

Select a Month

Check the conditions for any month of the year.

Best Time to Visit Alliston

Alliston's weather is most enjoyable during May, June, July, August and September, with comfortable temperatures from 20°C (67°F) to 27°C (80°F). The moderate conditions ensure pleasant weather for exploring the area. Expect varied weather during this period with rainfall between 78 mm (3.1 in) and 94 mm (3.7 in), providing a good balance of sunny and rainy days.

Wondering where to travel based on your weather preferences? Our recommendation tool helps you find destinations with your ideal climate conditions. Use our weather planner to find your perfect destination.