A very warm and humid air mass combined with light winds is creating poor air quality around Chicago and Detroit. These conditions may continue through the middle of the week.
Pollutants will be trapped in the lower layers of the atmosphere and can pose some health risks to people with respiratory problems.
While temperatures and humidity levels are forecast to remain high through Wednesday, more of a breeze should work to help disperse the pollutants later in the day.
However, some sensitive individuals will still want to exercise caution by limiting physical activity outside of a non-air-conditioned environment.
Cooler, less humid air will arrive following thunderstorms that can be locally severe late Wednesday night into early Thursday.
Tuesday was the first air quality action day this year in Illinois this year. Alerts in Illinois are issued by the Environmental Protection Agency.
The agency stated that people can reduce their contribution to the amount of pollutants by utilizing mass transit, postponing the use of fuel-powered lawn equipment and avoid refueling vehicles until later in the week, if possible.
Cold air and flurries are in store for the New Hampshire primary on Tuesday but should not significantly impact voter turnout.
Snow and slippery travel will arrive in the mid-Atlantic states prior to the middle of the week.
Waves of arctic air invading the eastern half of the United States this week will culminate with the coldest weather of the season so far for some areas by the Valentine's Day weekend.
Chilly air will visit New Orleans this year for the annual Mardi Gras celebrations and linger over the city until later in the week.
Warmer air will build from California to Washington into Tuesday raising temperatures to near-record levels and increasing the risk of wildfires in some areas.
Storm Imogen battered parts of England and Wales with powerful winds and downpours Sunday night into Monday.
New York City, NY (1934)
Absolute minimum -15 degrees.
Philadelphia, PA (1934)
Absolute minimum: -11 degrees.
Vanderbilt, MI (1934)
-51 degrees; record low for state.