ST. LOUIS – Tuesday marks the first official day of summer, but it’s also a forecast for an “orange” air quality day in the St. Louis region.

The “orange” rating is based on the U.S. Air Quality Index, which means the index values are between 101 and 150. During such advisories, members of sensitive groups may experience health effects, but the general public is less likely to be affected.

Such a rating means that certain populations, including people with lung diseases, older adults, and people who are active outdoors should consider precautions or limits with their outdoor activities.

The clean air partnership urges people to switch up their commutes to help with air quality, whether taking public transit, carpooling, vanpooling, walking, biking or telecommuting.