Extended Forecast - Environment Canada
Today Chance of showers Max: 28°C	Wed, 2 Jul Sunny Max: 28°C	Thu, 3 Jul A mix of sun and cloud Max: 25°C	Fri, 4 Jul Sunny Max: 26°C	Sat, 5 Jul A mix of sun and cloud Max: 29°C	Sun, 6 Jul Chance of showers Max: 28°C	Mon, 7 Jul A mix of sun and cloud Max: 26°C
Tonight Chance of showers Min: 17°C	Night Cloudy periods Min: 18°C	Night Clear Min: 16°C	Night Clear Min: 19°C	Night Cloudy periods Min: 22°C	Night Chance of showers Min: 21°C

Forecast

St. Catharines, ON (Issued: 5:00 AM EDT Tuesday 1 July 2025)

Today

A mix of sun and cloud. 40 percent chance of showers this afternoon with risk of a thunderstorm. Wind southwest 20 km/h gusting to 40 becoming light this morning. High 28. Humidex 33. UV index 9 or very high.

Tonight

Partly cloudy with 40 percent chance of showers early this evening. Otherwise clear. Risk of a thunderstorm early this evening. Low 17.

Wed, 2 Jul

Sunny. Wind becoming southwest 20 km/h late in the afternoon. High 28. Humidex 32. UV index 9 or very high.

Night

Cloudy periods. Low 18.

Thu, 3 Jul

A mix of sun and cloud. High 25.

Night

Clear. Low 16.

Fri, 4 Jul

Sunny. High 26.

Night

Clear. Low 19.

Sat, 5 Jul

A mix of sun and cloud. High 29.

Night

Cloudy periods. Low 22.

Sun, 6 Jul

Cloudy with 40 percent chance of showers. High 28.

Night

Cloudy periods with 40 percent chance of showers. Low 21.

Mon, 7 Jul

A mix of sun and cloud. High 26.