CanadaThe weather in August in Ottawa
It's warm in August in Ottawa with an average temperature of 25°C. Temperatures this month range from a low of 22°C to a high of 28°C. At night, you can expect temperatures between 14°C and 18°C.
Looking for sun? August isn’t a good month to be in Ottawa. The temperature is nice, but there’s too much chance of rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in August for Ottawa, Canada. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 34°C in 2016, Ottawa reached the highest temperature in August over the past 10 years. The lowest daytime temperature in this month was 14°C in 2023. The extreme nighttime temperatures ranged from a lowest recorded value of 8°C to a highest value of 23°C.
Rainfall amount
In August, there is an average of 196 mm of precipitation, spread over 19 days. The wind speed is around 3 Bft, mostly coming from the Southwest.
Daily weather in August for Ottawa
Click on any day in August to get detailed info about the usual weather on that day in Ottawa. Check out the historical temperatures and precipitation over the past 10 years on this day.
August weather comparison
| Ottawa | New York | |
|---|---|---|
| Average temperature | 25°C | 30°C |
| Max. temperature | 28°C | 31°C |
| Min. temperature | 14°C | -5°C |
| Total precipitation | 196 mm | 79 mm |
| Rainy days | 19 days | 13 days |
Start of August
The month of August starts in Ottawa with warm temps, averaging around 26°C during the day and nights around 17°C.
Mid August
By mid-August, daytime temps drop to around 25°C, with nights around 16°C. There’s a high chance of precipitation during this time.
End of August
By the end of August, the average daytime temperature in Ottawa is around 25°C, while nighttime temps are about 16°C. Expect regular precipitation, but if you’re lucky, you’ll also get some dry and sunny days.
Find affordable trips to Ottawa
UV index
The UV index is a maximum of 7 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Check out the climate of Ottawa for all months and discover the best travel time
Curious about the weather in other parts of Canada? Check out the climate and weather for spots like Vancouver, Toronto, Niagara Falls, or explore other destinations in Canada.
Temperature charts
These charts show the average temperatures in August in Ottawa, Canada. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in August in Ottawa
Temperature in August in Ottawa over the years
Precipitation charts
These charts show the average amount of precipitation in August in Ottawa, Canada. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in August in Ottawa
Total precipitation in August in Ottawa over the years
Daily UV index in August in Ottawa
This chart shows the average daily UV index in August in Ottawa, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in August in Ottawa
Have you been to Ottawa in August?
Share your weather experience in August in Ottawa.
Average weather in Ottawa by month
Click on a month below to see detailed weather info for Ottawa. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.