Climate Insights for Ottawa

The climate in Ottawa is cool. The average annual temperature is 7°C and approximately 1020mm of precipitation falls per year. Ottawa receives a notable amount of rainfall throughout the year, including during its driest month. Ottawa is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, June. The coldest months are February, January, December, when temperatures can drop to -12°C. Ottawa experiences heavy snowfall, typically from January through December.

Ottawa has a wide annual temperature range, spanning 40°C from the coldest to warmest months. The warmest month is August, when average highs reach 28°C and the mean temperature sits around 22°C. The coldest month is February, when overnight lows fall to -12°C and the daily average is -8°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs. The sharpest temperature change occurs between April and May, with a 11°C shift in average temperatures.

Ottawa is a moderately rainy area, receiving approximately 1020mm of precipitation annually, which averages out to around 85mm per month. The wettest month is October, averaging 146mm of rainfall. February and March also tend to see above-average precipitation. The driest month is May, with just 34mm. That's 112mm less than October, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall. Ottawa receives heavy snowfall, accumulating around 268cm annually from January through December. The snowiest month is February, with approximately 82cm. Winter travel should account for significant snow cover.

Ottawa is relatively calm, with an average annual wind speed of 3km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 4km/h, though still comfortable for most outdoor activities. The calmest conditions occur in September, with average winds dropping to 3km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 1km/h between the calmest and windiest months.

It is currently summer in Ottawa, which began on June 21, 2026. Ottawa is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 28°C, while the coldest stretch bottoms out in February near -12°C. Autumn is next, beginning on September 23, 2026 — 52 days from now.

The best time to visit Ottawa is during June, July and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 68mm per month. By contrast, August can be uncomfortably hot with highs reaching 28°C, while February is the coldest period with lows dropping to -12°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Ottawa based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.