Hot and humid summer: Weather Network releases summer outlook for Ottawa and eastern Ontario

The Weather Network’s summer forecast is calling for a hot and muggy one in Ottawa this year. CTV’s Katie Griffin reports.

It’s shaping up to be a hot and humid summer in Ottawa, with rainfall levels expected to be “near or above normal” through the next three months, according to the Weather Network.

The 2025 Summer Forecast was issued Wednesday morning, calling for “a much warmer pattern” of temperatures in early June and above-normal temperatures through the summer in Ottawa and eastern Ontario.

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“The upcoming season will truly deliver for those who have been longing for warmer weather,” the Weather Network said on its website.

“We expect that most of Canada will experience temperatures that are warmer than normal during the months of June, July, and August.”

The Weather Network says Ottawa will not see “persistent or severe heat throughout the summer,” but warm temperatures will arrive in June.

“After a sluggish and sporadic spring, a warm and humid summer is expected across the region, including London, Toronto, and Ottawa,” the Weather Network says.

“Early June will feature a quick transition to a much warmer pattern, and we could see our first heat wave before Canada Day. A few cool fronts will track across the region and deliver periods of more refreshing conditions. The higher humidity is forecast to keep overnight temperatures significantly warmer than normal, but daytime high temperatures are expected to be near normal or just slightly above normal.”

Last summer, the average daytime high in Ottawa was 24.5 C in June, 26.9 C in July and 25.5 C in August.

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The warm temperatures in June will come as Ottawa is set to go the entire month of May with the temperature not hitting 30 C. It will be the first time since 2019 the daytime high didn’t hit 30 C in May.

The Weather Network says Ottawa and most of Ontario “should experience stretches of drier weather during the summer.”

“We do not expect widespread or prolonged drought in this region.”

Rachel Modestino, a meteorologist with The Weather Network, says more humidity and heat could make for more severe storms.

“We are going to be more so on the edge of that heat dome so what that means is we could be seeing more of those stormy active weather periods, breaking up the kind of heat and humidity mugginess that the summer could bring,” she said.

“With that, because we do have that extra heat and humidity, it does provide more fuel for potentially severe storms this summer.”

With files from CTV News Ottawa’s Katie Griffin