Monday could bring about Canada's first 40°C day for 2023

A building ridge could allow the country to see its first 40-degree reading of the year by Monday afternoon

A few places have come perilously close to the symbolic 40-degree mark this summer, but nobody in Canada has seen this symbolic heat milestone so far in 2023.

Monday could end that streak.

We’re watching a formidable ridge building over Western Canada heading into the week, which could allow some communities to close in on an elusive 40°C reading.

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Building ridge looms over the West Coast

A hefty upper-level ridge will build southwest of Vancouver Island to start the week. Ridges are harbingers of above-seasonal temperatures because they foster sinking air, which warms up as it descends toward the ground.

Temperatures will soar well above seasonal for much of British Columbia as a result of this building ridge. Widespread heat warnings are in effect throughout portions of Vancouver Island, the South Coast, and east toward the Interior.

BC heat warnings Aug 13 2023 PM update

What looks to make this spell of hot weather unusual is that it won’t exactly be a dry heat. We’ll see some Pacific moisture lingering in the region as temperatures climb, which will make it feel unusually muggy for the duration of this heat event.

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The dew point here rarely climbs above 15°C during the summertime, but we could see dew point readings close to 20°C for some coastal communities by Monday. That’s the kind of uncomfortable humidity you’d expect to see on a sultry summer afternoon back east. So if you’re inclined to get some relief, head down to the beaches to get a cooler breeze.

Baron - BC Monday temps - Aug14

This setup is a tradeoff between simmering mugginess and searing heat. Folks along the immediate coast will have cooler temperatures but higher humidity, while communities farther inland will see hotter but less-muggy conditions.

Unfortunately, the Fraser Valley and Lower Mainland will be an exception to this pattern, as forecasters expect low-level moisture to pool in these areas, contributing to elevated humidex values.

Canada’s first 40°C of 2023 is almost here

Hot temperatures will arrive in earnest by Monday, ticking a few degrees warmer than what we saw on Sunday. These temperatures will be downright uncomfortable for most, and even dangerous heat for vulnerable populations throughout the region.

Daytime highs will climb into the upper 20s to near 30°C right along the coast, with the mid-30s likely as you travel inland up the Fraser.

Baron - Osoyoos BC temps - Aug14

All eyes are on Osoyoos and the southern Interior as temperatures are forecast to crest 40°C for the first time this summer across Canada. The warmest temperature recorded so far in Canada for 2023 goes to Etzicom, Alberta where the mercury reached 39.8°C back on July 25.

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Stay safe in the heat

Hot temperatures are the most dangerous weather you’re likely to face during the summer months. It’s a silent hazard that can sneak up on even the fittest individuals.

RELATED: How hot is too hot for the human body?

Heat Stroke and Exhaustion Symptoms

Use caution if you have to spend extended periods of time outdoors during the day. Stay aware of the symptoms of heat exhaustion and heat stroke, staying hydrated and taking frequent cooling breaks to prevent illness. Humidity will make it harder for the body to cool off during the heat of the day, and the muggy air will subdue any relief overnight.

WATCH: How extreme heat affects our body's ability to cool down

Cooling long range pattern

Temperatures will gradually cool a bit throughout the course of the week as a stronger onshore flow develops and the ridge flattens a bit. By the weekend, temperatures will be back closer to seasonal, with more cloud-cover and the return of some possible showers for the second half of August.

Baron - BC onshore flow - Aug14

Stay with The Weather Network for the latest on conditions across British Columbia.