Heavy rain and thunderstorms to soak Toronto Tuesday, with up to 75 mm possible

Toronto is bracing for a soaking Tuesday as a slow‑moving system threatens to dump as much as 75 millimetres of rain across the city by tonight, paired with the risk of thunderstorms that could intensify throughout the afternoon.

Severe thunderstorm watches for Toronto, Hamilton, Halton, Peel Regions, and Niagara ended early on Tuesday, though Environment Canada still cautioned for flooding in some areas as a result of torrential downpours.

“Driving conditions may be difficult,” Canada’s weather agency said. “Heavy rain can cause flash flooding and significant reductions in visibility. Severe thunderstorm watches are issued when conditions are favourable for the development of thunderstorms capable of producing damaging hail, wind or rain.”

Toronto’s short‑term outlook indicates periods of rain that are expected to intensify as the day progresses. Some areas of the GTA could see rainfall totals climb well beyond typical early‑spring levels, raising concerns about localized flooding in low‑lying neighbourhoods and areas with poor drainage.

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 15°C, with winds strengthening out of the southwest at 30–60 km/h.

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.

The next temperature swing for Toronto will occur on Friday, with a mix of sun and clouds and a forecast high of 15°C.

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