Overnight Temperatures to Bring Relief in Upcoming BC and Alberta Heat Wave

Police block the road into the wildfires near Entwhistle Alberta on May 7, 2023. The Canadian Press/Jason Franson

Alberta and British Columbia are bracing for an unseasonable heat wave with daytime highs soaring up to 15 degrees above normal over the coming days, though overnight temperatures are expected to provide some relief.

Armel Castellan, an Environment Canada meteorologist in B.C., says the coming heat wave shares some of the same characteristics as a so-called heat dome.

But he says it doesn’t have the potential to reach the same extreme highs as the deadly event in June 2021, when temperatures in B.C.’s Interior pushed into the 40s.

Castellan says the nights are still longer and cooler in mid-May than they were after the late-June heat dome two years ago, which the B.C. Coroners Service has said caused more than 600 heat-related deaths.

Still, Sarah Henderson with the B.C. Centre for Disease Control says it’s crucial for people susceptible to heat to stay hydrated as temperatures rise.

All of Alberta and most of B.C. are blanketed with special heat advisories from Environment Canada, and a special air quality statement is also in effect for much of western Alberta in response to smoke from dozens of early-season wildfires.

In B.C., the weather office says the unseasonably hot weather will begin Friday and continue through Tuesday, with the heat peaking Sunday and Monday.

A statement from the B.C. government says daytime highs in the Interior, Lower Mainland and Sea to Sky areas will hit the low to mid-30s, while Vancouver Island and the Sunshine Coast will see temperatures in the high 20s and low 30s.

The hot, dry conditions will start in Alberta this weekend, with the highest temperatures above 30 C expected from Sunday through Tuesday.

The Alberta government declared a provincial state of emergency last weekend in response to wildfires that have forced thousands of people from their homes.

The wildfire situation has also been heating up in B.C., particularly in the northeastern corner of the province near the boundary with Alberta.

A statement from the province says the burned area is four times larger than normal, due largely to three wildfires in the Peace River Regional District.

Meanwhile, high streamflow advisories cover much of B.C. as the coming heat wave raises the risk of flooding from rapidly melting snow in the mountains.

The B.C. government says key areas of concern include the Fraser River from Prince George through the Fraser Canyon, along with the Cariboo Mountains, North and South Thompson, Shuswap, Similkameen, Kootenay and Skeena regions.

B.C.’s River Forecast Centre is also maintaining a higher-level flood warning for the Bonaparte River near the village of Cache Creek, west of Kamloops, where residents are mopping up from flooding last week.