(Bloomberg) -- New York City’s hazy conditions will improve this weekend as lingering smoke from Canadian wildfires starts to fade and even gets washed out from showers in the forecast.

Air quality conditions across New York have improved although as of early Saturday were still deemed “unhealthy for sensitive groups,” notably older people or those with heart or lung disease, according to AirNow.gov, a US government website. 

An air quality alert remains in effect through midnight for the city’s five boroughs, as well as for upstate New York and parts of Connecticut, Massachusetts, Vermont, New Hampshire and Maine.

“We still have a very light amount of smoke left and it does appear that it’s creating a hazier sky,” said David Stark, a National Weather Service meteorologist in Upton on New York’s Long Island. “It is a lot lighter than it was yesterday and it is really going to be more of a sunny, hazy day in the city.”

Smoke from massive forest fires raging across Canada has been pouring south for weeks. In June, a thick plume of smoke turned the sky orange in New York, Washington and other East Coast cities, raising health concerns and even delaying or grounding flights for a time. 

Read more: Canadian Wildfire Carbon Emissions Reach Highest Level on Record

At least 510 fires are burning across Canada, with 253 deemed out of control, according to the Canadian Interagency Forest Fire Centre.

Earlier this week, Chicago, Cleveland, and many other Midwest cities, in addition to New York, saw air conditions plummet to unhealthy levels. Toronto and Canada’s capital Ottawa also suffered from smoke-filled air.

Starting Sunday a chance of showers will help improve the polluted skies, Stark said, and rain will help rid skies of any lingering smoke, especially at higher altitudes.

“The general idea here is improvement from the smokier conditions,” Stark said. The current forecast for the Fourth of July holiday on Tuesday is clear in New York with a high near 89F (32C) degrees.

©2023 Bloomberg L.P.