Behind strong to severe thunderstorms over the weekend, the cooler air mass over the northern Plains moves through the Great Lakes and into the Northeast.
Thunderstorms continued to be triggered by a front moving through the Ohio Valley for the end of the weekend. But cool air began trickling into the northern Plains.
After highs in the mid-80s on Saturday, temperatures were only rising to the upper 60s and lower 70s across the upper Midwest.
The cool air continues to advance south and east through the Great Lakes and into the Northeast.
By Monday, drastic temperature drops will be in store for Chicago, Detroit, Indianapolis, Buffalo and Pittsburgh. High temperatures in the low to mid 80s will plummet to the to the lower 70s, about ten degrees below average for the end of July.
Dew points will also drop into the 50s, making it less humid and comfortable.
The I-95 corridor will need to wait until Tuesday for the refreshing temperature change. The front finally reaching Washington D.C., Philadelphia, New York City, and Boston will keep it rather wet with showers and thunderstorms.
Across the Great Lakes and into the Northeast, it does remain unsettled into the middle of the week. A system brewing in the south-central U.S. on Wednesday will help to build in warmer temperatures by the end of the week.