Severe thunderstorm watch in effect for Ottawa-Gatineau

A look at the weather forecast in Ottawa for Sunday, July 6, 2025.

Stormy weather could arrive in the national capital region as temperatures hit the 30s Sunday afternoon.

Environment Canada has issued a severe thunderstorm watch for Ottawa and Gatineau for this afternoon into this evening with storms capable of producing 90 km/h wind gusts, nickel-sized hail and up to 30 millimetres of rain in an hour.

Heavy rain can cause flash flooding and significant reductions to visibility, the forecaster says. Strong wind gusts can damage trees, buildings and overturn vehicles.

Severe thunderstorm watches are issued when conditions are favourable for the development of thunderstorms capable of producing damaging hail, wind or rain.

Parts of western Quebec, including Wakefield, Cantley and Pontiac are under rainfall warnings with up to 100 millimetres of rain possible tonight and into Monday morning.

Emergency Management Ontario recommends that you take cover immediately if threatening weather approaches.

Ottawa weather

A mix of sun and clouds are expected today with a 40 per cent chance of showers late this afternoon and a risk of a thunderstorm. High 33 C. Humidex values will make it feel like 41.

It will be mainly cloudy tonight with a 60 per cent chance of showers and a risk of a thunderstorm. Low 20 C.

Monday will be mainly cloudy with a 30 per cent chance of showers changing to 70 per cent in the morning. Risk of a thunderstorm in the morning.

High 27 C with a humidex of 35.

Tuesday will be cloudy with a high of 24 C and a low of 16 C in the evening, about average for this time of year.

The long-range forecast shows temperatures remaining in the mid-20s with some rain and possible thunderstorms throughout the week.

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