TORONTO, March 31, 2026 — Residents across southern Ontario can expect severe thunderstorms and heavy rain on Tuesday evening, March 31, 2026, according to Environment and Climate Change Canada.
Canada’s trusted weather source is calling this a Yellow weather watch, warning of torrential downpours. 90 km/h wind gusts and up to toonie size hail, arriving this evening, and moving eastward into the night.
Report from Environment and Climate Change Canada:
Showers will be ending late this evening then cloudy with 40 percent chance of showers. Clearing before morning. Local amount 10 to 15 mm. Wind southwest 20 km/h becoming northwest 20 near midnight. Low plus 2.
A Yellow Status warning means hazardous weather may cause damage, disruption, or health impacts. Impacts are moderate, localized and/or short-term. Yellow alerts are the most common.
The areas affected are as follows:
Watford – Pinery Park – Eastern Lambton County; Sarnia – Petrolia – Western Lambton County; London – Parkhill – Eastern Middlesex County; Strathroy – Komoka – Western Middlesex County; Woodstock – Tillsonburg – Oxford County; City of Toronto; Newmarket – Georgina – Northern York Region; Vaughan – Richmond Hill – Markham; Listowel – Milverton – Northern Perth County; Goderich – Bluewater – Southern Huron County; Stratford – Mitchell – Southern Perth County; Mount Forest – Arthur – Northern Wellington County; Guelph – Erin – Southern Wellington County; Kitchener – Cambridge – Region of Waterloo; Innisfil – New Tecumseth – Angus; Orangeville – Grand Valley – Southern Dufferin County; Caledon; Mississauga – Brampton; Halton Hills – Milton; Burlington – Oakville
When thunder roars, go indoors! Lightning kills and injures Canadians every year.
Emergency Management Ontario recommends that you take cover immediately if threatening weather approaches.
Flash Flooding Possible
Heavy rain can cause flash flooding and significant reductions to visibility. Severe thunderstorm watches are issued when conditions are favourable for the development of thunderstorms capable of producing damaging hail, wind or rain. Please continue to monitor alerts and forecasts issued by Environment Canada.
To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm. For more information: ontario.ca/page/be-prepared-emergency.