Brockville residents can enjoy a sunny Monday, July 20, 2026, before showers move in on Tuesday, according to Environment Canada. The forecast shows a mix of clear skies and wet weather through the week, with temperatures staying near seasonal norms.
Monday will be sunny with a high of 26 C and a humidex of 29. Winds will pick up from the southwest at 20 km/h by late afternoon. The UV index is forecast at 8, which is considered very high. Environment Canada advises limiting time in the sun, particularly between 11 a.m. and 3 p.m., wearing UV-protective sunglasses, seeking shade, and reapplying sunscreen every two hours.
Tuesday brings a change as a mix of sun and cloud gives way to cloudy conditions by late morning, with showers developing. There is a risk of a thunderstorm in the afternoon. Temperatures will reach a high of 23 C early but drop to around 20 C later in the day. South winds at 30 km/h will gust up to 60 km/h before shifting to the west at 30 km/h and then to the south at 20 km/h later.
The chance of showers tapers off later in the week. Wednesday is forecast to have a 40 percent chance of showers with a high of 20 C, while Thursday and Friday look drier with highs of 24 C and 27 C. Saturday’s high is also 27 C. Sunday will be cloudy with a 30 percent chance of showers and a high of 24 C. Overnight lows will range from 13 C on Wednesday night to 18 C by Saturday night.
These temperatures are typical for Brockville in July, when the average high is 26 C and the average low is 16 C. The month normally sees about 9.3 hours of sunshine per day. As of 10 a.m. Monday, the temperature at the nearby Kemptville station was 22 C with a humidex of 24.
