We have been talking non-stop about the abundant heat across the U.S., especially out West. But crisp autumn air is making an appearance in a few spots, teasing the season change.

If anyone was looking at the TemperatureRadar Thursday morning, you likely noticed the dark green and even blue hues across the northern tier. The National Weather Service even had freeze warnings out for western North Dakota! These blue and green hues indicated cooler temperatures, some getting down to the freezing mark, for one of the first times this season. Those in the 40s had frost advisories, which stretched into the Upper Midwest.

The cool air is all thanks to a low-pressure trough ushering in cool air from the northwest, keeping temperatures as much as 5 degrees cooler than usual today for places like Bismarck, N.D., Rapid City, S.D., and Glasgow, Mont.

The cold front out ahead of the trough slowly marches east today, bringing overnight lows down into the 40s as far south as the Front Range, as seen on the TemperatureRadar. This is also causing high winds and bringing critical fire weather.

Drink your pumpkin spice latte while it's hot, though! Your 14-day forecast likely shows more summery heat ahead.