Ozone is the main concern that is causing an air quality alert Monday, the Minnesota Pollution Control Agency says — but what exactly is ozone?

An air quality alert will be in effect from noon to 9 p.m. on Monday for much of the state, and dozens of counties are under a red flag warning.

The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert Tuesday from 12 p.m. to 9 p.m. for ground-level ozone. This alert will impact Minnesotans in nearly two-thirds of the western part of the state. According to MPCA, sunny skies, warm temperatures and dry conditions creates an ideal environment for two types of pollutants.