Forecast - Environment Canada

Forecast

St. Catharines, ON (Issued: 6:11 PM EST Sunday 21 December 2025)

Tonight

Cloudy. Becoming partly cloudy late this evening. Wind west 30 km/h gusting to 50 becoming light after midnight. Low minus 8. Wind chill near minus 13.

Mon, 22 Dec

A mix of sun and cloud. Becoming cloudy in the afternoon. Wind becoming southwest 20 km/h gusting to 40 in the morning. High plus 4. Wind chill minus 10 in the morning.

Night

Cloudy with 40 percent chance of flurries in the evening and after midnight. Periods of rain or drizzle beginning after midnight. Risk of freezing drizzle over higher terrain overnight. Wind south 20 km/h. Low plus 1.

Tue, 23 Dec

Cloudy with 60 percent chance of drizzle. High plus 5.

Night

Clearing. Windy. Low minus 4.

Wed, 24 Dec

Sunny. High plus 2.

Night

Cloudy. Low plus 1.

Thu, 25 Dec

Cloudy with 40 percent chance of showers. High plus 5.

Night

Cloudy with 40 percent chance of showers. Low plus 4.

Fri, 26 Dec

Cloudy with 30 percent chance of showers. High plus 4.

Night

Cloudy with 30 percent chance of flurries or rain showers. Low zero.

Sat, 27 Dec

Cloudy with 30 percent chance of flurries or rain showers. High plus 1.

24 Hour Forecast - St. Catharines, ON

Date/Time	Temp. (°C)	Weather Conditions	LOP †	Wind (km/h)
22 December 2025
2 AM	-7	Partly cloudy	20	SW 10
3 AM	-7	Partly cloudy	20	SW 10
4 AM	-8	A few clouds	20	SW 10
5 AM	-7	Clear	20	SW 10
6 AM	-6	A few clouds	20	SW 10
7 AM	-5	Partly cloudy	20	SW 10
8 AM	-4	A mix of sun and cloud	20	SW 10
9 AM	-2	A mix of sun and cloud	20	SW 10
10 AM	-1	A mix of sun and cloud	20	SW 20 gust 40
11 AM	1	A mix of sun and cloud	20	SW 20 gust 40
12 PM	2	A mix of sun and cloud	20	SW 20 gust 40
1 PM	4	Mainly cloudy	20	SW 20 gust 40
2 PM	4	Cloudy	20	SW 20 gust 40
3 PM	3	Cloudy	20	SW 20 gust 40
4 PM	3	Cloudy	20	S 20
5 PM	3	Cloudy	20	S 20
6 PM	2	Chance of flurries	40	S 20
7 PM	2	Chance of flurries	40	S 20
8 PM	2	Chance of flurries	40	S 20
9 PM	2	Chance of flurries	40	S 20
10 PM	2	Chance of flurries	40	SE 10
11 PM	2	Chance of flurries	40	SE 10
23 December 2025
12 AM	1	Chance of flurries	40	SE 10
1 AM	1	Periods of rain or drizzle	80	S 20

† Likelihood of Precipitation (LOP) as described in the public forecast as a chance of measurable precipitation for a period of time. Nil: 0% Low: 40% or below Medium: 60% or 70% High: Above 70%

Extended Forecast - Environment Canada
	Mon, 22 Dec Mainly cloudy Max: 4°C	Tue, 23 Dec Periods of drizzle Max: 5°C	Wed, 24 Dec Sunny Max: 2°C	Thu, 25 Dec Chance of showers Max: 5°C	Fri, 26 Dec Chance of showers Max: 4°C	Sat, 27 Dec Chance of flurries or rain showers Max: 1°C
Tonight Partly cloudy Min: -8°C	Night Chance of flurries Min: 1°C	Night Cloudy periods Min: -4°C	Night Cloudy Min: 1°C	Night Chance of showers Min: 4°C	Night Chance of flurries or rain showers Min: 0°C