It's going to be a scorcher today in the Twin Cities and across a large portion of southern and western Minnesota as heat indexes soar near or past 100 degrees.

The National Weather Service has issued a heat advisory to be in effect from 1 to 8 p.m. Wednesday. Temperatures in the 90s combined with high humidity will create conditions ripe for heat illnesses such as cramps, strokes and exhaustion.

"Drink plenty of fluids, stay in an air-conditioned room and out of the sun, and check up on relatives and neighbors," the weather service's advisory reads. "Take extra precautions if you work or spend time outside. When possible, reschedule strenuous activities to early morning or evening."

The warning also comes with a reminder to not leave people or pets in closed vehicles.

Areas included in the heat advisory include Alexandria, St. Cloud, Willmar, Mankato, Worthington and Fairmont.

The highest heat indexes — summer's version of windchill — will be in an area from Madison in far western Minnesota to Willmar to north of Fairmont, where readings will reach the triple digits. In the Twin Cities, air temperatures in the low 90s and high humidity levels will combine to make it feel like 96 degrees, the weather service said.

Wednesday will mark the 12th time the mercury has hit 90 degrees or higher in the metro, the weather service said.

The dangerous heat will subside slightly Thursday as temperatures slide back to 89 degrees and 85 degrees Friday. But "it will be feeling downright tropical through this weekend," the weather service said.

More comfortable air will move in by early next week, with northwest winds helping cool temperatures to around 80 degrees by Monday and Tuesday.

Tim Harlow • 612-673-7768