St. Catharines Weather by Month

Average temperatures, rainfall and humidity for St. Catharines, Canada, month by month, built from OpenWeather’s historical records. Use it to see what a typical St. Catharines month looks like before you travel — then check the live St. Catharines forecast for the days ahead.

Warmest month

July

27°C average high

Coolest month

February

-6°C average low

Wettest month

October

77 mm of rain

Driest month

February

28 mm of rain

Average temperature and rainfall in St. Catharines by month

Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.

Month	Avg high	Avg low	Record low / high	Rainfall	Humidity	Wind
January	0°C	-6°C	-21°C / 15°C	37 mm	79%	21 km/h
February	1°C	-6°C	-23°C / 19°C	28 mm	77%	21 km/h
March	6°C	-2°C	-17°C / 23°C	46 mm	72%	19 km/h
April	12°C	3°C	-8°C / 28°C	73 mm	72%	17 km/h
May	19°C	10°C	-1°C / 31°C	63 mm	73%	14 km/h
June	24°C	15°C	7°C / 33°C	70 mm	72%	14 km/h
July	27°C	18°C	11°C / 35°C	61 mm	74%	13 km/h
August	26°C	17°C	9°C / 34°C	74 mm	76%	13 km/h
September	23°C	14°C	2°C / 33°C	60 mm	78%	14 km/h
October	16°C	9°C	-2°C / 29°C	77 mm	78%	17 km/h
November	9°C	2°C	-12°C / 25°C	50 mm	74%	19 km/h
December	4°C	-2°C	-19°C / 19°C	52 mm	79%	19 km/h

Best time to visit St. Catharines

The most comfortable time to visit St. Catharines is generally June and August to September, balancing mild daytime temperatures against the driest stretch of the year. The city has strongly marked seasons and rain concentrates around October, totalling about 690 mm a year.

Travellers who prefer heat should aim for July, when highs average 27°C. October is the month to avoid if rain would spoil your plans — it averages 77 mm, roughly 3× the rainfall of the driest month (February).

Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the St. Catharines forecast for what is happening now.