This week, residents of Toronto and the Greater Toronto Area (GTA) will experience a "weather roller coaster" — from stifling summer-like heat to winter-like frost, all within just a few hours.

The weather office warned that the intersection of a strong warm front and cold front will cause drastic weather changes. Not only will temperatures drop nearly 30°C, but there may also be severe thunderstorms, large hailstones, strong winds, and localized frost. Citizens are advised to remain highly vigilant and prepare in advance.

Monday: Spring-like Weather; Tuesday: Straight to Midsummer

On Monday (April 28), the weather in Toronto will be sunny and mild with temperatures approaching 20°C, making it suitable for heading to polling stations to vote. However, everything will take a sharp turn on April 29 (Tuesday).

Influenced by a low-pressure system from Colorado, the warm front quickly swept across Ontario, bringing unusually warm and humid air with southwest winds. Temperatures soared to 23°C, with a perceived temperature (humidity index) as high as 28°C. Compared to the average temperature of the same period, it was about 11°C to 13°C higher. Some areas in southwestern Ontario may even break through 30°C for the first time, setting a new record for Canada's highest temperature this year.

At that time, the air humidity is high, making it feel stuffy, and the UV index reaches 7. People should take sun protection measures when going out.

Afternoon Cold Front Arrives! Thunderstorms + Hailstones + Strong Winds Hit Together

But the short-lived "midsummer" will soon be mercilessly swept away by the strong cold front.

On Tuesday afternoon to evening, the cold front carries dry and cold air rapidly southward, colliding violently with the warm and humid air mass, causing extreme atmospheric instability.

The risk of severe thunderstorms rises sharply, with the main dangers including:

  • Strong Winds: Local wind speeds can exceed 100 kilometers per hour, potentially causing damage;
  • Heavy Rain: Although there may be short-term heavy precipitation, due to the fast-moving speed of the storm (over 60 kilometers per hour), the overall risk of flooding is relatively low;
  • Hailstones: Diameter 2-4 centimeters, with some areas possibly experiencing hailstones as large as ping-pong balls;
  • Tornado Possibility: Although the risk is not high, due to low cloud base and good wind shear conditions, isolated tornadoes may occur in local areas.

Weather experts predict that the most active thunderstorm activity will concentrate between 3 PM and 8 PM on Tuesday, especially in southern and eastern Ontario, where citizens need to keep an eye on sudden weather warnings.

Temperatures Plunge Nearly 30°C Overnight! Wednesday Morning Feels Like Winter

As the cold front completely sweeps across the province, temperatures will plummet drastically within hours.

In Toronto, temperatures will drop by 7°C between 10 PM and 1 AM on Tuesday night, and by Wednesday morning (April 30), temperatures will drop to around 3°C, with the perceived temperature dropping close to -1°C, as if winter has arrived overnight.

Although the daytime temperature in Toronto will rise to around 10°C on Wednesday, the nighttime temperature will drop again to 6°C, still feeling chilly.

Another Weather Roller Coaster This Weekend! Frost Risk Persists

After a brief warming up, a second cold front will strike again this weekend.

  • Thursday (May 1): The daytime temperature will still be low, expected to be only 9°C, with up to 15 millimeters of rainfall, making the whole day wet and cold;
  • Friday (May 2): The temperature will rise to 16°C, but accompanied by another round of rain, making the beginning of May feel wet and cold;
  • Weekend: The weather will improve, reaching 11°C on Saturday (May 3) and 16°C on Sunday (May 4), with sunshine returning.

It should be noted that the temperature in Ontario will remain below the seasonal normal level at the beginning of May, with frequent frost and even icing risks at night in suburban areas, especially having a significant impact on garden plants, crops, and sensitive crops. Farmers and gardening enthusiasts are advised to take protective measures in advance.

Source of News:

https://toronto.citynews.ca/2025/04/28/toronto-weather-forecast-this-week/

https://www.theweathernetwork.com/en/news/weather/forecasts/ontario-faces-greatest-supercell-storm-threat-of-the-year-so-far

https://www.theweathernetwork.com/en/news/weather/forecasts/from-july-to-january-in-ontario-in-a-matter-of-hours-on-tuesday

Original article: https://www.toutiao.com/article/7498931944336507411/

Disclaimer: The article represents the author's personal views. You are welcome to express your opinions in the button below [Upvote/Downvote].