What the next three months of summer weather will look like in Ontario

Following a turbulent month of May weather in Ontario, it looks like temperatures are finally beginning to settle as we inch closer to the official start of the summer season.

While temperatures will continue to occasionally dip to the low two-digit mark over the next few weeks, a new forecast offers an early look at how summer will play out this year.

Over the weekend, Environment and Climate Change Canada (ECCC) released its three-month temperature and precipitation probabilistic forecasts, which cover the period between June and August 2026.

The prediction system aims to "forecast the evolution of meteorological trend over the next seasons," and notably does not identify significant weather-related events and periods of heavy precipitation, such as storms.

According to the forecast models, temperature trends will vary slightly across Canada over the next three months, with most regions, including southern Ontario and the GTA, projected to see above-average warmth.

Based on ECCC's first map, the GTA and southwestern Ontario have a 70 to 80 per cent chance of seeing above-normal temperatures throughout the three-month period. On the other hand, southeastern Ontario has a slightly elevated chance of experiencing warmer temperatures this summer, between 80 and 90 per cent.

The system predicts that northern parts of the province have a 70 to 90 per cent chance of seeing above-normal temperatures between June and August.

In the second graph, models predict that the GTA has a 20 to 30 per cent chance of seeing near-normal temperatures during this three-month period. Southeastern Ontario has a lower chance, just between 10 and 20 per cent.

Based on the prediction system, the whole of Ontario has between a 0 and 10 per cent chance of witnessing below-normal temperatures throughout the summer.

These predictions contrast with The Weather Network's summer 2026 forecast, released last week, which characterized the upcoming summer season as "changeable," "reactive," "noncommittal," and "inconsistent."

While the weather channel notes that final temperatures might finish close to the seasonal mark, southern Ontario is still expected to see below-normal temperatures this summer. On top of this, above-normal precipitation is also expected in the region this summer.

Another forecast, namely the Old Farmer's Almanac, predicts that southern Ontario will trend more "cool and rainy" throughout the summer, which could disrupt any prolonged stretches of heat. Similar to The Weather Network's forecast, the Almanac also expects that we'll see wetter-than-usual conditions in Ontario this summer.