DENVER -- Smoke from wildfires in the western U.S. has moved into Colorado, leaving a noticeable haze sitting over most of the Front Range on Monday.
Fires are burning in Montana, Wyoming, Idaho, Washington, Oregon and California. More than 500,000 acres have burned in Montana.
Upper-level winds carried the smoke into Colorado and it settle in because of an inversion, the National Weather Service said.
An air quality advisory was issued for communities along the Front Range and eastern Plains by the Colorado Department of Public Health.
The haze is expected to decrease later Monday afternoon and a cold front that will knock temperatures into the upper 60s on Tuesday could help clear things out.