DENVER (KDVR) — Concentration levels of ozone are expected to be at their highest Monday and Tuesday afternoon into early evening along the Front Range, the state health department reported.

With moderate levels in place, an ozone action alert day has been issued through 4 p.m. Tuesday. Wildfire smoke from Western wildfires will fluctuate over the next 24 hours, as well.

The air is deemed unhealthy for sensitive groups, which means those people should refrain from extensive exercise or activity. Those with sensitivity to air pollution should limit activity due to the smoke in the air, specifically in northern Colorado.