The combination of high heat and high humidity could be dangerous for southern Wisconsin residents and visitors Friday and Saturday, according to forecasts.
The National Weather Service issued a heat advisory that takes effect at noon Friday and continues to 7 p.m. Saturday, because temperatures are expected to reach the mid-90s both days.
When the humidity is figured in, the heat index readings will be in the 100- to 105-degree range, not good for being outside.
"Heat illnesses are possible," the advisory said. "Drink plenty of fluids, stay in air-conditioned rooms, stay out of the sun and check on relatives and neighbors."
If outside, wear lightweight and loose-fitting clothing, and try to keep strenuous activities to a minimum or do the activities in the early morning or evening.
Thursday started out in a fog, with visibility down to zero in some locales, but the fog wasn't going to last, giving way to mostly sunny skies and a high of 86, said 27 Storm Track meteorologist Branden Borremans.
The hot Friday and Saturday should be sunny both days, with a slight chance for showers and thunderstorms late Saturday night.
Sunday should be cooler with a high in the low to mid-80s, also with a chance for showers and thunderstorms.
Borremans said the heat won't go away the first week of July, with highs of 87 on Monday, 90 on Tuesday, 93 on the Fourth of July on Wednesday, and 94 next Thursday.
Skies should be mostly sunny Monday through next Thursday.
Wednesday's high of 80 was 1 degree below normal and 17 degrees below the record high of 97 for June 27, set in 1933.
The low was 65, 5 degrees above normal and 23 degrees above the record low of 42 for the date, set in 1992.
A trace of rain fell at the airport, keeping the June and meteorological summer (June through August) total at 5.49 inches, 1.39 inches above normal.
The record rainfall on June 27 was 3.33 inches in 1869.
Since Jan. 1, Madison has received 22.33 inches of precipitation (rain and melted snow), 6.40 inches above normal.