An air quality advisory has been issued for Metro Vancouver and the Fraser Valley as temperatures soar across the region.
A statement from Metro Vancouver on Tuesday said high concentrations of ground-level ozone are expected to persist throughout the week due to the hot and sunny weather, which is forecast to continue through the weekend.
Smoke from the Nohomin Creek wildfire burning near Lytton, B.C. — which has grown to more than 2,300 hectares in size and is not contained — is also contributing to hazy conditions in the Lower Mainland, the advisory noted.
Residents are advised to avoid strenuous outdoor activities if breathing is difficult during the mid-afternoon and early evening hours, when ground-level ozone levels are at their highest levels. Walking instead of running is advised.
People with underlying respiratory health issues, along with pregnant women, infants, children, older adults and outdoor workers and people experiencing homelessness are considered to be at elevated risk of exposure.
Ground-level ozone occurs when nitrogen oxides, created by pollutants from burning fuels, react in the air with volatile organic compounds in the presence of sunlight.
Heat warnings now cover all but the edges of the province, with Environment Canada warning that Tuesday could be one of the hottest in an ongoing heat wave.
Temperatures in the Lower Mainland exceeded 30 C, while parts of central and southeastern B.C. reached up to 40 C Tuesday, including the Fraser Canyon area surrounding Lytton.
— with files from The Canadian Press