Mild
Average highs are around 20°C, so days are mild rather than hot.
September verdict
Cornwall (Ontario), Canada in September
Weather score44Mixed
Mixed for holiday weather
Average highs are around 20°C, so days are mild rather than hot. Sunshine averages 5.4h per day, enough for a balanced month. Rainfall averages 93mm, so some wet days are possible.
September weather
Monthly averages
Temp
20°C
Rain
93mm
Sun
5.4h
Weather score
44
Mixed
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 93mm, so some wet days are possible.
Some sun
Sunshine averages 5.4h per day, enough for a balanced month.
Map
Weather map
Compare Cornwall (Ontario), Canada with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September20°C average high
September sits in the warmer part of the year, so midday sightseeing can feel heavier than in cooler months.
Warmest monthsMay to September
This stretch sets the upper range for average daytime heat.
Rain
September93mm average rain
September is wetter than Cornwall (Ontario)'s yearly average, so flexible plans matter more.
Driest monthsJanuary to July and September to December
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September5.4 hours average sun
September sits close to Cornwall (Ontario)'s yearly sunshine average, so it is a middle-of-the-pack month for bright days.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
Weather score
September44 weather score
September sits close to Cornwall (Ontario)'s yearly weather-score average, giving a typical overall read on the month.
Best weather monthsJune to August
These months have the strongest weather score in the monthly averages.
Hotels near Cornwall (Ontario), Canada
Marriott
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Courtyard Ottawa EastOttawa, Ontario, Canada
TownePlace Suites by Marriott Ottawa BarrhavenOttawa, Ontario, Canada
AC Hotel Ottawa DowntownOttawa, Ontario, Canada