A massive summertime ridge of high pressure over the British Columbia Interior will persist for several more days. The ridge, in combination with slightly lower pressure west of Vancouver Island, is providing ideal conditions for extremely hot weather on the South Coast.
The normal refreshing daily sea-breeze will disappear as warmer air from the interior descends to the coast, further warming in the process. The ensuing offshore winds also prevent cool marine air over the Pacific Ocean from moving inland and spreading through the inner coastal waters. Each day the stagnant air heats up a little more under the powerful summer sun.
Under such stagnant conditions, air pollutants accumulate, especially over Metro Vancouver and the Fraser Valley. The hot weather and degraded air quality persist until the pressure pattern reverses, the wind shifts to onshore, and cooler marine air begins flowing through the Strait of Juan de Fuca. That shift will likely occur on <xxxxday>. By <nextday> temperatures will be 5 to 10° Celsius lower and the air quality vastly improved.
Until then, afternoon temperatures will climb into the mid-thirties daily.