ClimateAverages

Ottawa Weather in September

JanFebMarAprMayJunJulAugSepOctNovDec
Right now
21°C
Light rain · feels like 21°C
Humidity
83%
Wind
4 kph NW
UV
0.2
Rain
0%
Updated Jul 9, 07:45 AMWeather data by WeatherAPI.com
September daytime high
20.1°C
September overnight low
8.5°C
September average
14.3°C

In September, Ottawa typically sees daytime highs of 20.1°C and overnight lows around 8.5°C. Compared to the annual average high of 11.1°C, September runs +9.0°C.

vs. annual avg high
+9.0°C
Rank among 12 months
#4 warmest
Hottest year overall
2023

Where September ranks in Ottawa

JanFebMarAprMayJunJulAugSep20°OctNovDec

FAQ

What is the average temperature in Ottawa in September?

September in Ottawa averages a daytime high of 20.1°C and an overnight low of 8.5°C.

Is September warm or cold in Ottawa?

September runs +9.0°C compared to Ottawa's annual average high of 11.1°C, ranking #4 of 12 months by warmth.

What should I pack for Ottawa in September?

Plan for daytime highs near 20.1°C and cooler evenings around 8.5°C.

Other months for Ottawa

JanuaryFebruaryMarchAprilMayJuneJulyAugustOctoberNovemberDecember

September in nearby cities

TorontoLondonMississaugaNorth YorkScarboroughHamiltonBramptonEtobicokeWindsorMarkhamOshawaVaughan