BURNABY, B.C. -- For a few hours Friday, Metro Vancouver air quality was as bad as it has ever been, as smoke from dozens of wildfires burning out-of-control in California and Oregon blew in and settled over the city.

In many neighbourhoods, the thick blanket of smoke blocked out the downtown skyline and the North Shore mountains — prompting warnings from Environment Canada and Metro Vancouver.

“Right now, we’re experiencing some of the worst air quality that we’ve ever experienced in this part of the region,” said Ken Reid, Metro Vancouver’s superintendent of environmental monitoring and sampling.

For most of the day, Vancouver ranked number four on a list of cities with the worst air quality in the world — eclipsed only by three U.S. cities closer to the wildfires burning in U.S. pacific states.

The smoke from those fires will hang around for at least a few more days, with the possibility even more could blow in from off-shore.

“There may be periods of time where there’s less smoke, there may be periods of time where there’s more smoke,” said Reid. “If some smoke comes in that’s aloft, at higher elevations, it may create dramatic sunsets, orange skies, or even block out the sun from time to time.”

The conditions are not expected to get as bad as San Francisco, where an eery orange haze settled over the city earlier this week, creating apocalyptic images.

Still, the situation here is bad enough that even healthy people are being encouraged to avoid strenuous activity until the air quality advisories are lifted.

Conditions are particularly bad for people with underlying conditions like asthma, and it could also worsen symptoms for people sick with COVID-19.

Just heading inside may not be enough to help because the particles are small enough to make their way inside peoples’ homes even with the windows and doors closed.