Here is the forecast for Tamarack Ottawa Race Weekend in Ottawa

(CTV News Ottawa)

Runners can expect cooler-than-normal temperatures in Ottawa this weekend as they prepare to participate in the Tamarack Ottawa Race Weekend.

More than 36,000 people have signed up to participate in the races on Saturday and Sunday.

• Here’s what you need to know ahead of Ottawa Race Weekend 2025

Ottawa will see a high of 12 C on Saturday for the 2K, 5K and 10K events at race weekend, while the outlook for Sunday calls for a high of 17 C for the marathon and half marathon.

• What’s happening in Ottawa this weekend: May 23-25

Environment Canada’s forecast calls for a high of 11 C today, which is 10 degrees below normal for this time of year.

Showers will continue through the day.

The rain will continue tonight. Low 6 C.

Saturday will be mainly cloudy with a 70 per cent chance of showers. High 12 C.

Sunday will have a mix of sun and cloud with a 30 per cent chance of showers. High 17 C.

Warmer temperatures will arrive in Ottawa on Monday. The capital will see a mix of sun and clouds with a high of 21 C.

The normal temperatures for this time of year are a high of 21 C and a low of 10 C.

A good time to plant

While you may not want to spend much time outside during the cool weather, experts say it’s a good time to plant your garden.

“The cooler weather and the rainy weather is actually a great time to plant,” Colin Matassa of Robert Plante Greenhouses told CTV Morning Live on Friday.

“Perennials, trees and shrubs, they love that kind of weather.”

The lowest temperature over the next week is 6 C on Friday night. Overnight lows will be between 10 C and 12 C starting Sunday, according to Environment Canada.

Ottawa River

This week’s rainfall is expected to slow the decline in water levels on the Ottawa River.

The Ottawa River Regulation Planning Board says flows are “declining gradually” along the main stem of the Ottawa River.

“Rainfall expected over the next few days should slow the decline in levels and flows,” the board said.

“Conditions at all locations along the main stem of the Ottawa River are expected to remain above average for this time of year over the coming days.”