Weather in Ottawa: September
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Average day temperature: | 78.5°F |
| Average night temperature: | 59.1°F | |
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Number of sunny days: | 19 days |
| Day length: | 11.8 - 13.1 hours | |
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Number of rainy days: | 1 day |
| Precipitation totals: | 0.5 in. | |
| more information | ||
14 days
forecast
forecast
| Ottawa |
weather in
October
October
| Ottawa |
Air temperature in September, °F
Show year:
2025
2024
2023
The highest day temperature during September of 2025 was 92°F. At the same time the lowest night temperature was 39°F. Daily and nightly averages during September were 81.4°F and 55.8°F.
Sunny, partly cloudy and cloudy days
Mostly all days in September are sunny but cloudy days are also possible.
Precipitation total in September, in.
Precipitation total value in Ottawa in September is 0.5 in. Other months of the year show relatively similar values.
Wind speed in September, mph
The average wind speed value in September is 8.3 mph It makes September one of the least windy months of the year.
Average sunny hours
This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 9.2.
Best time for vacation in Ottawa
Ottawa on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Ottawa
Local time: 07:12
December 14, sunday
0900
1°F
SE
9 mph
9 mph
1200
9°F
SE
9 mph
9 mph
1500
14°F
SE
8 mph
8 mph
1800
10°F
E
5 mph
5 mph
2100
5°F
NE
5 mph
5 mph
December 15, monday
0000
3°F
NE
6 mph
6 mph
0300
3°F
NE
9 mph
9 mph
0600
9°F
N
12 mph
12 mph
