Millions of Americans across Oregon, Washington and California continue to breathe in air considered unhealthy and even hazardous by the Environmental Protection Agency. The smoke is a minor inconvenience relative to the loss of life and homes suffered by some. But after nearly a month of breathing ash-saturated air, many are wondering when they will finally taste fresh air again.

For those on the coast, some relief may come as early as Friday. National Weather Service Meteorologist Roger Gass says a shift could start pushing smoke back inland before the weekend.

“This is very fire dependent,” cautioned Gass. “There are some indicators that as early as Friday winds will become westerly aloft, and push the smoke east.”

Gass said that could mean more smoke trapped in places like California’s Central Valley, or we could see plumes drifting even farther east.

Any widespread clearing, of course, is largely dependent on firefighters knocking down flames from a series of devastating fires that have already burned millions of acres across the three coastal states and killed at least seven people. California alone has seen six of the twenty largest fires in state history this year.

Temperatures have cooled from the record-shattering highs seen over Labor Day weekend, potentially lessening the new fire danger, but active fires continue to spew particulate matter into the air across several states.

The California Air Resources Board suggests residents close their windows, use a certified filter to clear the air and avoid using stoves and other gas-powered appliances indoors during periods of poor air quality.

More of those bad air days are likely in the weeks ahead as the traditional peak of fire season hits.

Gass cautions that even a shift in the wind won’t bring the current conditions back to normal.

“We’re not going to see completely clear skies for a while,” Gass said.