Heat and humidity will peak this Wednesday afternoon, just ahead of a cold front from the west. Temperatures should top out in the low to middle 90s with a heat index reaching 100-degrees –plus in at least a few areas. As the cold front nears and moves through northeast Illinois into northwest Indiana, a band of potentially strong to severe thunderstorms is likely to accompany the frontal boundary with the possibility of damaging winds and large hail.

Following the front, Canadian-source high pressure will spread over our area with northeast winds bringing cooler, less humid air Thursday. Indications are this break in heat and humidity will be just temporary, as the high pressure should move off to the east with southwesterly winds pulling hot humid air back. into the Chicago area this weekend.