Ottawa saw a cooler, drier than usual May

Tulips begin to bloom at Commissioners Park in Ottawa on May 4, 2026. (CTV News Ottawa)

May in Ottawa was slightly cooler than average and saw less rain than normal, according to Environment and Climate Change Canada.

The monthly weather review for Ontario shows May was cooler than usual across the province, with temperatures one to two degrees below average. In Ottawa, the monthly mean temperature was 12.5 C, or 1.1 degrees below the normal mean of 13.6 C.

“Cooler-than-normal days dominated the first half of May; however, May 4-5 offered a brief warm break provincewide. On May 18, a warm spell spread across the province and many record daily maximum temperatures were set,” the weather agency said.

Ottawa’s hottest day of the month was May 26, when a temperature of 29.5 C was recorded.

Precipitation was 60 per cent of the monthly average, with 44.7 millimetres of rain officially recorded in May. The average total for the month is 75 mm.

Some storms moved through the region in May.

“Evening thunderstorms produced strong wind gusts as they moved from Lake Huron to the upper Ottawa Valley on May 18. Trees and hydro poles were downed. Near Mattawa, debris from downed trees closed Highway 533 for several hours, and a campground was evacuated; paramedics transported one camper to the hospital,” Environment and Climate Change Canada said.

Data for Kingston also showed a cooler, drier month, with temperatures 1.2 degrees below average and a rainfall total 33 per cent lower than normal.

The outlook for June indicates a “very high likelihood of warmer-than-normal conditions across the province,” Environment and Climate Change Canada said.

“In contrast, the precipitation outlook is less certain. Below-normal precipitation is forecast for most of the province, with the greatest likelihood from James Bay southwest to Lake Superior and east of Georgian Bay.”

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