Special weather statement for weekend: Heavy rainfall expected across Montreal

Montreal will move from mild spring weather into a potentially impactful rainfall event this weekend, with 15 to 25 millimetres of rain expected Sunday as conditions shift sharply across the region.

Friday starts off mainly cloudy, with fog patches dissipating early in the morning before skies clear in the afternoon. The temperature will reach a high of 17 Celsius, with a UV index of 6. Clear skies are expected overnight, with a low of 6 C.

Warm and sunny conditions take hold Saturday, with a high of 21 C and a UV index of 7. Winds will strengthen from the southeast at 30 km/h, gusting to 50 km/h. Clouds will increase later in the day, with rain beginning Saturday night and temperatures holding at a low of 6 C.

The weather turns significantly on Sunday as a system moves into southern Quebec, bringing periods of rain and windy conditions. Rainfall amounts between 15 and 25 millimetres are possible. With river levels already high and the ground saturated, the additional rain could lead to rising water levels and localized flooding, including pooling in low-lying or poorly drained areas. The temperature will fall to a high of 7 C before clearing Sunday night, with a low of minus-2 C.

Cooler air settles in Monday, bringing a mix of sun and cloud and a high of 3 C. Clear skies Monday night will see temperatures drop further to minus-5 C.

Conditions remain somewhat unsettled into Tuesday, with a mix of sun and cloud and a 30 per cent chance of showers. The high will reach 6 C, with cloudy periods and a 30 per cent chance of showers continuing into the night, along with a low of 2 C.

Residents are advised to monitor conditions closely through the weekend, particularly in areas prone to flooding, as water levels may rise with the incoming rain.