Fox News Weather Center

PHOTOS: Wildfire Smoke Fills the Sky Over Northwest US

Dozens of wildfires raging across the northwestern United States have spread a vail of smoke over the region, blocking the sun and causing health issues.

Smoke-filled skies have lead to poor air quality across the region that the Department of Environmental Quality warns could be bad for certain groups of people.

Those with heart or lung problems are especially vulnerable to the poor air quality and should avoid the smoke by saying indoors and keeping the doors and windows closed. People should also avoid strenuous outdoor activity in the smoky conditions.

So far this year, more than 7.4 million acres have been burned by wildfires, well above the normal average of 5.2 million acres, according to the National Interagency Fire Center.

The NIFC also detailed how firefighters have come from as far away as Australia and New Zealand to battle the blazes across the Pacific Northwest.

Homes and businesses may be threatened as the massive wildfires continue to spread.

Currently, none of the 72 active large fires in the United States are contained, many of which burning across the West.

Unfortunately, firefighters will have to wait until the weekend for rain to return to the region, helping to put out the wildfires over the Pacific Northwest.

Winds associated with the rain may help to spread some of the fires, but at the same time, will help to rid the region of the smoke that has lingered overhead since late last week.

Washington National Guard Pilot Wears Helmet Cam on Chelan Firefighting Mission

Smoke from the western wildfires has spread eastward over part of the Plains. (Photo/NASA)