New York City's Central Park has not hit 90 yet, but if it does Friday, it will be about a month late for the first 90-degree reading of the year.
Kansas City, Missouri, hit 90 degrees Thursday for the first time this year, about a month later than normal.
The heat will continue for the next couple of days in the Northeast, before it finally cools off Sunday.
It will only get hotter in the Midwest and the Plains this weekend with highs in the mid-90s by Sunday all the way to Minneapolis.
Heat advisories have been issued for five states in the Plains from South Dakota to Missouri for this weekend.
Temperatures are expected to sore into the mid-90s, but with the high humidity it will feel like it's close to, or over, 100 degrees.