The heat wave baking Wisconsin has a long way to go, with the worst still to come.
The National Weather Service issued a heat advisory Wednesday for most of southern Wisconsin, in effect from noon Thursday to 11 p.m. Friday, as temperatures are expected to hit the low 90s Thursday and the mid- to upper 90s Friday.
Heat index values will be in the 100s, possibly up to 110 on Friday.
"Heat illnesses will be possible with prolonged outdoor exposure to the heat," the advisory said. "The elderly, children, and those on certain medications are especially at risk for heat illnesses."
People should stay in air conditioned rooms, stay out of the sun and check on relatives and neighbors to make sure they are OK.
"Take extra precautions if you work or spend time outside," the advisory said. "When possible, reschedule strenuous activities to early morning or evening."
In southwest Wisconsin, specifically Crawford, Grant and Richland counties, an excessive heat watch will be in effect from noon Thursday to 7 p.m. Saturday, with temperatures expected to reach the mid-90s to 100 each day.
Adding to the heat is the chance of severe thunderstorms and heavy rain Wednesday night.
A flash flood watch is in effect in southwest and western Wisconsin, with slow-moving storms expected to dump up to 4 inches of rain from Grant County up to Buffalo County.
Storms are likely to move into south-central Wisconsin as well, with a slight risk for severe weather. The main hazards here would be damaging winds and large hail.
The Weather Service said Madison could see up to an inch of rain from the storms.
27 Storm Track chief meteorologist Bob Lindmeier said there's a chance for an isolated shower Wednesday afternoon with the high reaching 89.
Lindmeier is looking at highs of 92 on Thursday, 95 on Friday and 93 on Saturday.
There are slight chances for showers and thunderstorms Friday and Saturday, with better chances Saturday night and Sunday as cooler air starts to move into the area.
Sunday's high is expected to reach 83, then the heat wave will be broken to start the week, with highs of 74 on Monday and Tuesday, under sunny skies.
Tuesday's high reached 90 in Madison, 8 degrees above normal and 8 degrees below the record high of 98 for July 16, set in 2012.
The low of 71 was 10 degrees above normal and came at 11:59 p.m. The record low on July 16 was 48, set in 1966 and tied in 1972 and 2014.
A late night shower dropped 0.08 of an inch of rain at the airport, bringing the July rainfall total up to 2.22 inches, 0.02 inches below normal.
The record rainfall on July 16 was 2.68 inches in 1950.
For the meteorological summer of June through August, Madison has received 7.38 inches of rain, 0.60 inches above normal.
Since Jan. 1, Madison has received 23.19 inches of precipitation (rain and melted snow), 4.58 inches above normal.