Temperatures in September
It's pleasantly warm in September in Ottawa with an average temperature of 19°C. Temperatures this month range from a low of 12°C to a high of 23°C. At night, you can expect temperatures between 4°C and 13°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Ottawa in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in Ottawa with mild temperatures, averaging around 18°C during the day and nights close to 9°C. You can expect regular precipitation, but there’s also a chance for some sunny days in the first days of the month.
Mid-September
By mid-September, the average daytime temperature rises to around 21°C, with nights close to 10°C. Not much precipitation expected during this period. It’s mostly dry with sunshine.
End of September
By the end of September, the average daytime temperature in Ottawa will be around 20°C, with nights close to 9°C. A shower might show up, but overall the weather will be dry and sunny.
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Precipitation in September
In September, there is an average of 78 mm of precipitation, spread over 10 days. Of the total precipitation, about 0,2 cm falls as snow in September. The wind speed is around 3 Bft, mostly coming from the Southwest.
The average precipitation chance is 33% per day this month.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for Ottawa. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Ottawa in September |
London | ||
|---|---|---|---|
 Average Temperature |
19°C | 20°C | |
 High Temp |
23°C | 22°C | |
| Low Temp |
12°C | 17°C | |
 Total Precipitation |
78 mm | 44 mm | |
| Rainy Days |
10 days | 8 days | |
 Total Snowfall |
0,2 cm | 0 cm | |
| Snowy Days |
1 day | 0 days | |
August
UV index
The UV index is a maximum of 6 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.
Is September a good time to visit Ottawa?
Want nice weather? Then September is a great time to be in Ottawa. You’ll have pleasant temperatures and not too much rain this month.
Check out the climate of Ottawa for all months and discover the best travel time
Curious about the climate in other parts of Canada? Check out the weather and climate in places like Vancouver, Toronto, Niagara Falls, or have a look at other destinations in Canada.
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Daily Temperature in September in Ottawa
This chart shows the average daily temperatures, both day and night, for each day in September in Ottawa, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Ottawa
The chart below shows the average daily precipitation in September for Ottawa, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 10 days of rain in Ottawa.
Daily Snowfall in September in Ottawa
This chart shows the average daily snowfall in September in Ottawa, measured in centimetres. The bottom of the chart shows the days of the month. The data is based on historical measurements and gives an idea of the average snowfall in September.
Daily UV Index in September in Ottawa
This chart shows the average daily UV index in September 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.
Temperature in September in Ottawa Over the Years
This chart shows the average temperature in September in Ottawa, measured in degrees Celsius, over the past years.
Total Precipitation in September in Ottawa Over the Years
This chart shows the average precipitation in September in Ottawa, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Snowfall in September in Ottawa per year
This chart shows the average snowfall in September in Ottawa, measured in centimetres, over the past years.
Daily climate in September for Ottawa
Click on a specific day in September for detailed info on the typical weather on that day in Ottawa. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Ottawa
Have you been to Ottawa in September?
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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.
