Humidex in Ottawa could hit low 40s this week

A heat warning is in effect for Ottawa as a stretch of hot, humid weather begins on Tuesday.

Environment Canada says temperatures this week could reach highs in the low 30s with humidex values in the low 40s.

"A multi-day heat event begins today," the weather agency said in a statement. "Areas near the lakes could be slightly cooler than regions further inland.”

The extreme heat is expected to last until Thursday.

Much of southern and eastern Ontario is under the heat warning, as is most of northern Ontario.

The heat and humidity could also affect air quality, according to Environment Canada. Ottawa’s air quality health index is expected to reach 4, or moderate risk, on Tuesday.

The city of Ottawa has not announced any cooling centres for residents, particularly homeless residents, but said in a statement residents can visit air-conditioned city facilities, pools, beaches and splash pads to cool off.

"The City of Ottawa is working closely with Ottawa Public Health (OPH) to keep residents safe during the multi-day heat event expected to begin today. Residents can seek refuge from the heat at various air-conditioned City facilities, including community centres, Ottawa Public Library branches and City administration buildings," said a statement attributed to recreation and facilities general manager Dan Chenier. "Residents are also encouraged to choose safe and supervised aquatic activities at indoor swimming pools, splash pads, wading pools, beaches and outdoor swimming pools."

Ottawa Public Health offers a list of places to cool off on its website.

HYDRO OTTAWA WARNS OF DELAYS

Warmer weather brings the possibility of power outages as demand on the grid increases. 

Hydro Ottawa declined an interview with CTV News Ottawa but said in a statement it is keeping a close eye on the forecast.

"As we head into the height of summer, we understand that residents may be concerned about potential power outages. Hydro Ottawa continues to monitor the weather closely and have our teams on standby to restore power should there be any disruptions. Restoration times may be delayed as a result of the labour disruption, but our customers can be assured that every effort will be made to perform the work safely and in a timely manner, day or night."

Hundreds of Hydro Ottawa employees with the International Brotherhood of Electrical Workers went on strike last week. The IBEW says the major issues in the dispute are compensation, benefits and the working environment at Hydro Ottawa, including issues around safety and understaffing.

OTTAWA FORECAST  

The weather forecast for Ottawa calls for a mix of sun and cloud on Tuesday. A fog advisory is in effect for the capital, but the fog patches are expected to dissipate this morning.

Tuesday’s high will be 30 C with a humidex of 39. There will be a 40 per cent chance of showers and risk of a thunderstorm in the afternoon and evening.

The overnight low will be 20 C.

A lifeguard is seen at Britannia Beach as people take to the waters and shores of the Ottawa River in Ottawa on Tuesday, July 4, 2023. A heat warning has been issued for the nation's capital and Ontario. (Sean Kilpatrick/THE CANADIAN PRESS)

Wednesday's high could reach 32 C with a humidex of 39. It will be a sunny start to the day tomorrow, with a mix of sun and cloud and a chance of showers in the afternoon. There will also be a risk of a thunderstorm.

Wednesday’s overnight low will be 20 C.

Thursday could hit a high of 30 C.

There are no record-breaking high temperatures in the forecast. Record highs for July 4, 5, and 6 in Ottawa are around 34 C.