Toronto is under a severe thunderstorm watch after the week began with a burst of spring warmth, but a mid‑week temperature crash is expected to briefly pull the city back toward winter.
Environment Canada has issued a severe thunderstorm watch for Toronto, Hamilton, Halton and Peel Regions and Niagara.
The storms are expected to start tonight and last through Tuesday with torrential downpours, frequent lighting and potential hail. Up to 50 millimetres of rain is expected to fall in some areas.
Forecasters say the next several days will feature dramatic swings — from near 20 C warmth to freezing rain risks — as southern Ontario rides the rollercoaster of early spring.
The low will drop to 9 C overnight, keeping the air warm enough for a soaking rain rather than anything wintry.
Tuesday is shaping up to be the most active day of the week in Toronto and across the GTA. A surge of warm, unstable air will push temperatures to 17°C, with winds strengthening out of the southwest at 30–60 km/h. Forecasters expect 10–20+ mm of rain, and the risk of thunderstorms continues through the day.
This system taps into a broad plume of moisture, meaning rainfall could be locally higher in heavier downpours. The mild air hangs on into the evening before temperatures fall to 5°C overnight.
Wednesday: A transition day with a wintry twist
Wednesday brings a brief break in the action, with sunny breaks and a high near 8°C. But the calm won’t last. As colder air pushes in from the north, the city faces the risk of freezing rain or ice pellets on Wednesday evening and overnight.
This transition zone — warm air aloft, cold air at the surface — is classic early‑spring volatility. Even a short period of freezing rain could create slick conditions late Wednesday and early Thursday.
Thursday turns fully wet again, but this time with a colder, more persistent rain. Temperatures hold near 3°C, and 15–30 mm of rainfall is possible through the day. Winds shift easterly at 20–50 km/h, adding a raw, chilly feel.
Click here to sign up for the CityNews Weather Guarantee and to check out Toronto’s extended forecast.
