The Twin Cities is in store for its hottest day of the year Tuesday, and it could be a record-setter.

But even if the mercury doesn't push past the standing record for June 14 of 98 degrees set in 1987, Tuesday will be toasty. High humidity and strong winds accompanying the sudden burst of heat will make it feel like 100 degrees or hotter, the National Weather Service said.

An excessive heat warning for the seven-county area will be in effect from 11 a.m. to 8 p.m. Tuesday as heat index values — summer's version of the wind chill — will top out near 103 degrees, the Weather Service said.

"Extreme heat and humidity will significantly increase the potential for heat-related illnesses, particularly for those working or participating in outdoor activities," the Weather Service said in issuing its warning. "Drink plenty of fluids, stay in an air-conditioned room and stay out of the sun."

With the sultry conditions expected, the Weather Service also is reminding people to never leave young children or pets in unattended vehicles.

The Twin Cities has only seen two 90-degree days this year, with the warmest at 92 degrees on May 12. Temps also hit 90 degrees on May 28, according to the Minnesota State Climatology Office.

In southern Minnesota, showers and thunderstorms Monday morning gave way to steamy conditions. A heat advisory for index values close to 105 degrees goes into effect at 2 p.m. Monday and will remain in effect until 8 p.m. Tuesday in Brown, Watonwan, Blue Earth, Martin and Faribault counties, including the cities of New Ulm, St. James, Mankato, Fairmont and Blue Earth, the Weather Service said.

Several Minneapolis public schools will shift to an e-learning day due to the forecasted heat. Buildings without air conditioning that will be closed to the public Tuesday include Bryn Mawr, Field, Hiawatha, Kenny, Kenwood, Longfellow, Northrup and Pratt community schools, both the upper and lower campus of Lake Harriet School, Sheridan Arts Spanish Dual Immersion School and Roosevelt High School.

A brief reprieve from the sticky conditions is on tap for the middle of the week, but the blast furnace will return in the metro with highs on Saturday near 92 degrees and 96 degrees on Sunday, the Weather Service said.