Weather · Ottawa, Canada
Ottawa Weather in September
September in Ottawa averages 21°C by day and 13°C at night, with about 87mm of rain. That makes it one of the best months to visit.
Avg high
21°C
70°F
Avg low
13°C
55°F
Rainfall
87mm
#6 wettest of 12
What to pack
Layers, plus a jacket for mornings and nights. Bring a compact umbrella for the odd shower.
Timing a trip around the weather? A Local Friend in Ottawa builds it around the season for you.