Ontario (OR) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Ontario.
Climate overview of Ontario
Ontario, Oregon, United States of America, sees big temperature differences between seasons, with July peaking at 35°C (95°F) and January dropping to 2°C (36°F).
Rain/snowfall is extremely rare, with only 232 mm (9.1 in) falling across the entire year.
Ontario Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Ontario - and find the best time to visit.
Monthly Temperature in Ontario
Visitors to Ontario can expect significant temperature changes throughout the year. Average maximum daytime temperatures range from a very warm 35°C (95°F) in July, the warmest time of the year, to a chilly 2°C (36°F) during cooler months like January.
At night, you can expect temperatures ranging from 16°C (61°F) in July to around -6°C (21°F) during January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Ontario
Ontario experiences desert-like conditions in terms of precipitation with almost no rain/snowfall, generally receiving 232 mm (9.1 in) annually. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, December it receives moderate snow/rainfall, averaging 45 mm (1.8 in) of precipitation, recorded across 13 snowy/rainy days. In contrast, the driest month July brings less rainfall, with 3.8 mm (0.1 in) over 2 rainy days. For more details, please visit our Ontario Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Best Time to Visit Ontario
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: April, May, June, September and October
- Warmest weather: July
- Fewest rainy days: July, August and September
- Seasonal pattern: Very little rainfall for most of the year, with very warm summers and cold winters
- Coldest conditions: January, with freezing nights around -6°C (21°F).
Frequently asked questions about the climate in Ontario
What is the best time to visit Ontario?
April, May, June, September and October typically offer the most optimal weather in Ontario. In contrast, January, July and December tend to have less optimal conditions. Ontario has very little rainfall for most of the year, with very warm summers and cold winters.
What temperatures can I expect in Ontario?
Daytime highs range from 2°C (36°F) in January to 35°C (95°F) in July. Nighttime lows range from -6°C (21°F) to 16°C (61°F). Temperatures vary considerably through the year.
How much rain does Ontario get?
Annual rainfall is around 232 mm (9.1 in). December is the wettest month with 45 mm (1.8 in), while July is the driest with 3.8 mm (0.1 in). In the coldest months, precipitation may fall as snow/rain.
Ontario 3-Day Forecast
Ontario (OR) 3-Day Forecast
Ontario on the map
Ontario is highlighted - select any city to see its climate.
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