All of central and southern Minnesota and western Wisconsin, including the St. Croix Valley, is under a heat advisory from 11 a.m. to 9 p.m. today with near triple-digit highs expected, according to the National Weather Service.
Southwest winds are expected to bring hot air across the upper Mississippi River Valley, said an NWS statement.
“Humidity levels will not be overly oppressive, but the actual temperature will b near 100 degrees at most locations by mid-afternoon,” forecasters said. “Heat indices will range from 100 to 105.”
The NWS statement urges people to schedule strenuous activities to early morning or evening, wear light weight, loose-fitting clothing when possible, drink plenty of water, and schedule plenty of rest breaks in shaded or air-conditioned areas.
Temperatures were already in the upper 70s to near 80 this morning across the Valley. Highs are expected in the upper 90s to 100 in the region under sunny skies.
A cold front sagging south out of northern Minnesota makes thunderstorms possible tonight through Thursday, the NWS said.
“A few isolated severe storms are possible but coverage will be scarce,” the NWS said. “A few storms may produce isolated large hail and damaging winds.”
There is a 20 percent chance of storms after 1 a.m. Tuesday, with lows forecast to fall to the low 70s, the NWS said.
Tuesday will be slightly cooler, with a high in the upper 80s under partly sunny skies and a 30 percent chance of showers and thunderstorms. There is a slightly better chance of rain before 1 a.m. Wednesday with lows dropping to the mid-60s.
Wednesday will be sunny with a high near 83. Showers and thunderstorms are back in the forecast Wednesday night and Thursday with a low near 65 and a high Thursday near 85.
Hot weather returns to the Valley in time for the weekend with highs in the low to middle 90s Friday through Sunday and lows in the low to middle 70s.