Montreal is under a severe thunderstorm watch and the week ahead doesn’t look much better

If you had any outdoor plans for this afternoon, you may want to rethink them.

Environment Canada issued a Yellow Watch for severe thunderstorms over the Montreal Island area Wednesday morning, warning that weather conditions this afternoon and evening are favourable for the development of severe thunderstorms capable of producing heavy rain.

The watch carries a moderate impact level with high forecast confidence, and the agency isn’t mincing words: heavy rain could cause flash flooding and significant reductions in visibility, and when thunder roars, go indoors.

As of 11:00 AM, skies are mostly cloudy with a temperature of 23.6°C, humidity at 74% and a humidex of 30. The tendency is falling, so conditions are expected to deteriorate as the day goes on.

What the rest of the week looks like

Wednesday’s storms are just the opening act. Here’s what Environment Canada is forecasting through next Tuesday:

Wednesday (today): Showers with a risk of thunderstorms late this afternoon and into the evening. Amounts of 10 to 20 mm possible. High 25, humidex 32.

Wednesday night: Showers continuing, with the risk of thunderstorms early in the evening. Low 20.

Thursday, June 11: A few showers ending in the morning, then a mix of sun and cloud with a 30% chance of showers. High 28, humidex 37, UV index very high.

Thursday night: Cloudy with a 60% chance of showers. Low 21.

Friday, June 12: A mix of sun and cloud with a 60% chance of showers. High 29.

Friday night: Showers. Low 17.

Saturday, June 13: Sunny. High 26.

Saturday night: Clear. Low 16.

Sunday, June 14: Periods of rain. High 24.

Monday, June 15: A mix of sun and cloud. High 24.

Tuesday, June 16: A mix of sun and cloud. High 25.

Saturday is the one bright spot in the stretch, with sunshine and a high of 26°C before another round of rain moves back in Sunday.

It’s worth noting that the cool, unsettled pattern tracks with what forecasters have been saying about this summer more broadly. A MétéoMédia report from late May projected that Quebec’s summer 2026 could be the coolest in nine years, driven by a shift from La Niña to El Niño.

More precipitation days than usual and fewer sustained heat waves are both part of that forecast, so this week is less of an anomaly and more of a preview of what the season has in store.