Alliston (ON) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Alliston.
Climate overview of Alliston
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. The city also has warm summers and very cold winters. Sunshine peaks in July, when the city sees around 9.8 hours of sunshine per day.
Alliston Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Alliston - and find the best time to visit.
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
Daily hours of sunshine
Daily percentage of sunshine
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
Best Time to Visit Alliston
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, June, July, August and September
- Warmest weather: July and August
- Most sunshine: July
- Seasonal pattern: Warm summers and very cold winters
- Coldest conditions: January, with freezing nights around -11°C (12°F).
Frequently asked questions about the climate in Alliston
What is the best time to visit Alliston?
May, June, July, August and September typically offer the most optimal weather in Alliston. In contrast, January, February, March, November and December tend to have less optimal conditions. Alliston has warm summers and very cold winters.
What temperatures can I expect in Alliston?
Daytime highs range from -1°C (30°F) in January to 27°C (81°F) in July. Nighttime lows range from -11°C (12°F) to 15°C (59°F). Temperatures vary considerably through the year.
How much rain does Alliston get?
Annual rainfall is around 919 mm (36 in). June is the wettest month with 94 mm (3.7 in), while February is the driest with 60 mm (2.4 in).
How sunny is Alliston?
Alliston receives around 2,184 hours of sunshine per year. July is the sunniest month with 295 hours, while January is the cloudiest with just 78 hours. Overall, Alliston enjoys abundant sunshine.
Alliston 3-Day Forecast
Alliston on the map
Alliston is highlighted - select any city to see its climate.
Popular this month
Where to go in August - average daytime high across popular destinations.
Bucket list
Need travel inspiration? Check out our bucket list articles and be inspired.
The 5 most beautiful lakes in Canada
Explore Canada's stunning lakes: Lake Louise, Lake Superior, Maligne Lake, Emerald Lake, and Lake Okanagan, each offering unique beauty and activities.
Canoeing the south Nahannii
The South Nahanni in the northwest of Canada is one of the most impressive wilderness rivers in the world. Canoeing the south Nahanni is something you must add to your bucket list.
See Polar Bears in Churchill Canada
Thousands of bears gather at the small town of Churchill. In the evening the northern lights give a light show against the dark evening sky. An unforgettable experience.
Banff National Park
Snowy mountains, clear blue lakes and green forests make Banff National Park a wonderful bucket list destination. The pristine wilderness is a mecca for walkers.