Weather in Ontario

Ontario's climate is considered continental, with temperatures ranging from humid in the south, with chilly winters and warm summers, to sub-arctic in the north. Due to Ontario's size, temperatures may vary tremendously from region to region. 

Temperatures are officially measured in degrees Celsius (C). 
 
On average, the coldest month of the year is January and the warmest is July. In summer, temperatures can soar above 30 C (86 F), while in winter they can drop to below -13 C (9 F), and often colder in the north.

Weather reports

Visit the Weather Network or Environment Canada for current Ontario weather updates and local forecasts.

The Great Lakes Marine Forecast includes marine forecasts (temperatures, wind speeds, wave heights, visibility) along with weather warnings for various regions in Ontario (May–October).

Ski and snow reports

Snow reports and ski/snowboard conditions for major ski resorts in Ontario are available through Ski Ontario from December through to March.

Preparing for the weather

The weather changes dramatically from season to season and it’s essential you are prepared. Here are some suggestions for clothing and other things you’ll need to comfortably enjoy all four seasons in Ontario. Keep in mind, that temperatures may often be vastly different between Southern and Northern Ontario, so you’ll want to check the weather forecasts at your specific destinations.

Summer (June, July and August)

• Bug spray 

• Sunblock

• Sun hat and sunglasses

• Light jacket, sweater and long pants for evening

Fall (September, October and November)

• Rain jacket

• Waterproof boots

• Sweaters

Winter (December, January and February)

• Winter coat

• Warm, waterproof boots

• Hat, scarf and warm gloves

• Warm socks 

• Snow pants for outdoor activities

Spring (March, April and May)

• Light or rain jacket

• Waterproof boots