There is an air quality advisory for Connecticut in effect until 11 p.m. Monday.
Several towns and cities are expected to reach level yellow and level orange.
The Connecticut Department of Public Health says yellow is considered generally safe, but could impact some people with an unusual sensitivity to particle pollution.
The department defines orange as unhealthy for sensitive groups including people with heart or lung disease, older adults, children and teenagers.
For anyone going into neighboring New York, officials are also issuing an air quality health advisory for New York City — expected to reach level orange.
Health and environmental officials recommend taking extra breaks when you're outside. If you have asthma, they say to keep medication on hand.
For the latest forecast on air quality index, you can visit AirNow or the CT DEEP online guide.
The CT DPH has more information about the different levels of air quality and what each color means.