Mild
Average highs are around 25°C, so days are mild rather than hot.
Weather Guide
Cornwall (Ontario), Canada Average Monthly Weather
Weather score39Poor annual avg
Best months: July, August, June
Across the year, average daytime temperatures are around 11°C, sunshine averages 5.2h per day, and rainfall totals about 957mm.
Annual weather
Annual averages
Temp
11°C
Rain
957mm
Annual total
Sun
5.2h
Weather score
39
Poor avg
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 99mm, so some wet days are possible.
Some sun
Sunshine averages 7.3h 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
August25°C average high
August is one of Cornwall (Ontario)'s warmest months, with daytime heat above the yearly average.
Warmest monthsMay to September
This stretch sets the upper range for average daytime heat.
Rain
August99mm average rain
August is one of Cornwall (Ontario)'s wettest months, so rain is likely to be a major planning factor.
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
August7.3 hours average sun
August is brighter than Cornwall (Ontario)'s yearly average, though the strongest sunshine usually sits closer to the peak months.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
Weather score
August63 weather score
August scores above Cornwall (Ontario)'s yearly average, so the overall weather mix is stronger than most months.
Best weather monthsJune to August
These months have the strongest weather score in the monthly averages.
Hotels near Cornwall (Ontario), Canada
Marriott
Courtyard Montreal West Island/Baie D’UrfeBaie D'Urfe, Quebec, Canada
Fairfield Inn & Suites Ottawa AirportOttawa, Ontario, Canada
Residence Inn Ottawa AirportOttawa, Ontario, Canada
Courtyard Ottawa EastOttawa, Ontario, Canada
TownePlace Suites by Marriott Ottawa BarrhavenOttawa, Ontario, Canada
AC Hotel Ottawa DowntownOttawa, Ontario, Canada