Forecast

Extended Forecast - Environment Canada
Today Mainly sunny Max: 27°C	Mon, 29 Jun Sunny Max: 28°C	Tue, 30 Jun Sunny Max: 33°C	Wed, 1 Jul Sunny Max: 34°C	Thu, 2 Jul Sunny Max: 34°C	Fri, 3 Jul Chance of showers Max: 34°C	Sat, 4 Jul Chance of showers Max: 27°C
Tonight Clear Min: 15°C	Night Clear Min: 20°C	Night Clear Min: 21°C	Night Clear Min: 22°C	Night Clear Min: 22°C	Night Chance of showers Min: 21°C

Today: Mainly sunny. Fog patches dissipating this morning. Wind becoming northeast 20 km/h this afternoon. High 27. Humidex 32. UV index 9 or very high.
Tonight: Clear. Wind northeast 20 km/h becoming light this evening. Low 15.
Mon, 29 Jun: Sunny. High 28. Humidex 34. UV index 9 or very high.
Night: Clear. Low 20.
Tue, 30 Jun: Sunny. High 33.
Night: Clear. Low 21.
Wed, 1 Jul: Sunny. High 34.
Night: Clear. Low 22.
Thu, 2 Jul: Sunny. High 34.
Night: Clear. Low 22.
Fri, 3 Jul: A mix of sun and cloud with 30 percent chance of showers. High 34.
Night: Cloudy periods with 60 percent chance of showers. Low 21.
Sat, 4 Jul: A mix of sun and cloud with 30 percent chance of showers. High 27.

24 Hour Forecast - St. Catharines, ON

Date/Time	Temp. (°C)	Weather Conditions	LOP †	Wind (km/h)
28 June 2026
7 AM	18	Mainly sunny	0	VR 5
8 AM	19	Mainly sunny	0	NE 10
9 AM	21	Mainly sunny	0	NE 10
10 AM	22	Sunny	0	NE 10
11 AM	24	Sunny	0	NE 15
12 PM	24	Sunny	10	NE 15
1 PM	25	Sunny	10	NE 15
2 PM	25	Sunny	10	NE 15
3 PM	26	Sunny	10	NE 20
4 PM	26	Sunny	10	NE 20
5 PM	27	Sunny	10	NE 20
6 PM	26	Sunny	10	NE 20
7 PM	24	Sunny	10	NE 20
8 PM	23	Sunny	10	NE 20
9 PM	21	Clear	0	VR 5
10 PM	19	Clear	0	VR 5
11 PM	17	Clear	0	VR 5
29 June 2026
12 AM	16	Clear	0	VR 5
1 AM	16	Clear	0	VR 5
2 AM	15	Clear	0	VR 5
3 AM	15	Clear	0	VR 5
4 AM	16	Clear	0	VR 5
5 AM	16	Clear	0	VR 5
6 AM	17	Sunny	0	VR 5

† 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%