After what seemed like a long and hot June and July, a bit of autumn preview has settled across the East and Midwest. Give the air conditioner a break and open the windows.

The TemperatureRadar is showing big cool down extending from the Upper Midwest and the Great Lakes into the Mid-South and central Mississippi Valley and eastward into the Northeast and Mid-Atlantic. This follows on the heels of a big cold front that settled southward late Sunday.

Highs will only be in the middle 70s in Boston, New York, Philadelphia and Washington, with Chicago barely touching 70 degrees.

Overnight lows tonight will drop into the 50s throughout the East and into the Southeast and Mid-South, with many spots in the Midwest possibly dropping into the upper 40s. Grab the extra blanket from the linen closet.

These overnight temperatures are more typical of late September and 15 to 20 degrees below seasonal normal. A few spots will even set new daily temperature lows.

This autumn preview will stick around through Wednesday, with a return to more summer temperatures to close out the work week and head into the weekend. Enjoy it while it lasts!