Extreme heat and humidity are blanketing Canada this weekend from Saskatchewan to Quebec — and Environment Canada's long-term forecast says warmer-than-normal weather can be expected to persist throughout the summer.

"I recommend avoiding the sun and doing anything strenuous outdoors," CBC weather specialist Jay Scotland said. "Hazy, hot, humid. It is going to be absolutely sticky today."

Temperatures of 30 C and above are expected from western Quebec to southern Saskatchewan over the next few days, and in many places the humidity will make it feel like 40 or higher.

Heat and health

Extreme heat events can result in several heat-related illnesses, causing heat exhaustion, fainting, cramps or heat stroke.

A heat stroke, also called sun stroke, is a medical emergency — if you suspect heat stroke, dial 911. A victim suffering heat stroke will have a body temperature above 40 C, but they will have stopped sweating. Other symptoms include:

  • Throbbing headache.
  • Dizziness
  • Confusion
  • Nausea
  • Red, hot and dry skin.

Precautions include: staying indoors in air-conditioned areas, avoiding direct sunlight, drinking lots of water, taking a cool bath or shower, limiting physical activity, avoiding alcohol, and checking for side effects of medication.

Source: Health Canada

Environment Canada has issued special weather statements in Quebec, Ontario and Manitoba warning of the heat, and Toronto issued a heat alert, advising people to check in on friends, neighbours and family members who are at risk from heat-related illnesses.

The temperatures are expected to persist well into the workweek.

Winnipeg will be one of the hottest places, with the forecast high no lower than 30 C for the next seven days. Scotland said warm weather qualifies as a heat wave when there are three consecutive days of at least 32; the Manitoba capital is forecast to have at least four.

The weather system is part of a heat wave that gripped much of the United States for the last two weeks. Temperatures have hit as high 46 C, buckling roads in Oklahoma, killing cattle in Texas and being blamed for the deaths of 39 people.

Health officials say it's the combination of temperature and humidity that people need to watch.

"As the humidity climbs and our humidity factors go up, our ability to deal with the heat actually goes down and more and more people become affected by that," said Dr. Maurice Hennink of the Regina-Qu'Appelle Heath Region, where temperatures are expected to peak at 36 on Tuesday.

The heat goes on

People hoping for relief are out of luck, according to Environment Canada's forecast for August.

Warmer-than-normal temperatures are predicted across the country for the dog days of summer and it's going to dry up out west, Environment Canada senior climatologist David Phillips said. 

That comes as especially good news in Alberta and British Columbia, where cloud and rain have put a damper on summer  so far.

Most of the West is in for drier-than-normal conditions through mid-August, Phillips said.

"If anyone deserves some good weather, it's British Columbia and Alberta. They've been clearly short-changed," he said. "We've reached the midway point and they haven't had any summer yet. They had a miserable winter and a miserable spring."

Cooler weekend on the extreme ends of the country

But B.C. won't get its reprieve just yet. While the middle of the country bakes this weekend, the forecast for Vancouver and much of British Columbia calls for showers and temperatures around 20 C.    

Atlantic Canada has also had a cooler than usual summer.

"The extreme ends of the country have been seeing slightly lower temperatures than average," CBC meteorologist Shelly James said.

Vancouver is expected to see temperatures around 18 C this weekend, which is three to four degrees below average for this time of year.

St. John's will see the thermometer hit 20, which is nevertheless a huge jump from Thursday's temperature of 8.

With files from The Canadian Press