Walsh's office is also urging the public to limit outdoor activity to morning and evening hours and to use sunscreen in addition to staying hydrated.
More storms will fire up this afternoon from IL to MI - including in Chicago and Milwaukee - with damaging winds, large hail and brief tornadoes possible. Furthermore, if the heat persists past the holiday, this heat wave could approach some of the notably long heat waves on record in locations such as New York City and Albany, New York. Low temperatures in some of the major metro areas will struggle to dip below 80 degrees during their peak heat this weekend.
A heat advisory is issued when the anticipated heat index- a formula based on air temperature and humidity - reaches or exceeds 100 degrees.
Forecasters say it will be warm and muggy along the ME coast, but still cooler than communities farther inland.
Heat index values will exceed 100 degrees Saturday and might reach 100 degrees again on Sunday, the weather service reported. Temperatures have to exceed 90 degrees for at least three consecutive days to count as a heat wave.
The unsafe heat that is on the way raises some issues that everyone should be aware of.
Another round of hot air will move into the central USA on the Fourth of July.
It is very easy to get dehydrated when it is so hot and humid.
Make sure to also check on any elderly neighbors as well as any kids and pets to make sure they are okay in the heat. Wear light weight and loose fitting clothing when possible and drink plenty of water.
THURSDAY | Variable clouds with PM t'storms possible.
With all the heat and humidity destabilizing the atmosphere, strong to severe storms are definitely possible and all of southeast Wisconsin has been placed in the slight risk for severe weather.
Saturday is expected to be even hotter, and a little more humid with plenty of sunshine.
Sunday night - Partly cloudy, with a low around 74.
Clear, warm, and sticky.
Forecasters say that Tropical Storm Fabio, off the west coast of Mexico, will develop into a hurricane on Monday and track to the west-northwest.