Wildfire smoke affected air quality across Colorado Sunday, with much of the state seeing moderate-to-heavy levels of smoke from four major fires.

The Colorado Department of Public Health and Environment issued an air quality advisory for northern and central Colorado Sunday, warning that smoke could make residents sick and those with respiratory conditions should stay inside.

Winds are expected to shift Sunday evening to blow toward the east, likely bringing periods of moderate-to-heavy smoke to the areas to the south and east of the Cameron Peak and Williams Fork fires. The Cameron Peak fire is burning in Larimer County and the Williams Fork fire is burning about 15 miles southwest of Fraser.

Projections from the National Weather Service at Boulder predict the majority of the Front Range will experience heavy smoke Sunday night, gradually easy overnight and into Monday morning.

Monday will see heavy smoke around Grand Junction, Rifle, Aspen, Steamboat Springs and Vail, according to the weather service.