REGINA — A dangerous, multi-day heat wave is settling over southeast Saskatchewan, bringing oppressive humidity and the potential for record-breaking temperatures through the weekend.
Environment Canada has issued an orange-level heat warning for the Yorkton region and the entire southeastern corner of the province, where humidex values are expected to reach a stifling 45.
Julien Corriveau, a meteorologist with Environment Canada based in Winnipeg, said a stark contrast exists between the eastern and western sides of the province due to moisture levels. While western Saskatchewan is under a yellow heat advisory, the eastern regions are bearing the brunt of the humidity.
"The difference would be that we're expecting the worst of the heat to be through southeastern Saskatchewan and also south-central Saskatchewan," Corriveau said. "The humidity will be higher in eastern areas, so it will feel hotter because of that."
Field evaporation fueling the humidity
According to Corriveau, the extreme humidity is a combination of weather systems and local conditions. A southerly airflow is drawing sticky air up from the United States, but substantial recent rainfall in eastern Saskatchewan and western Manitoba is amplifying the effect.
"Because of the hot temperatures that will evaporate a lot of the water on the fields, that will also add to the humidity," Corriveau said. "So yes, it is a factor in the high humidity we're expecting."
Daytime highs are forecast to exceed 32 degrees Celsius for the next four days, with Saturday and Sunday expected to be particularly hot and muggy as temperatures climb into the mid-to-high 30s.
The heat could rewrite the history books in the Parkland region. While major centres like Regina face historical benchmarks above 41 degrees, Yorkton is flirting with record territory.
"For Yorkton, the records are around 33, 34 this weekend," Corriveau noted. "So if a high of 35 on Sunday, that could be a record."
No relief at night
Public health officials warn that extreme heat is a health risk for everyone, but the danger is compounded by unusually high overnight temperatures. Environment Canada reports that overnight lows will not drop below 16 degrees, though Corriveau said some areas may stay as warm as 20 degrees.
"Most nights are quite warm," Corriveau said. "That just exacerbates the heat because you can't really cool off much at night. So definitely try to stay cool as best as you can."
Residents are urged to check on older adults, people living alone, and vulnerable neighbours multiple times a day. Early signs of heat exhaustion include headaches, nausea, dizziness, dark urine, and intense fatigue. Health officials state that heat stroke is a medical emergency, and anyone displaying confusion, red and hot skin, or a loss of consciousness should receive immediate 911 medical attention.
Manitoba Parklands next in line
The extreme weather system is also tracking eastward. While areas north of Yorkton and most of Manitoba began Friday under a special weather statement, full heat warnings are being deployed for the Manitoba Parklands, and areas north of Yorkton Friday afternoon.
"The heat, only 27 for the Dauphin area today, but reaching mid-30s in the Parklands tomorrow, Sunday, possibly even into Monday," Corriveau said.
Relief from the extreme conditions will arrive gradually. Temperatures on the Saskatchewan side are expected to ease back toward seasonal averages on Monday, while the heat may linger in Manitoba until Tuesday or Wednesday. However, daytime highs will remain warm, staying in the mid-to-upper 20s for the rest of the week.
Environment Canada noted there is a small, isolated risk of thunderstorms triggered by daytime heating on Friday and over the weekend, but a regional high-pressure system is expected to keep the storms very scattered, with no widespread impact on ongoing regional flood situations.
For health-related advice regarding the heat wave, Saskatchewan residents can call HealthLine 811.
