FIRST ALERT WEATHER DAY: First hard freeze tonight

RICHMOND, VA (WWBT) - It's been a mild autumn so far, with many areas in Central Virginia not even getting a frost yet.

That's about to change. With a brief, but strong shot of arctic air arriving Friday, winter will hit hard Friday night. At least the winds will diminish tonight, but temperatures will plunge under clear skies and very low humidity.

Early morning temps around sunrise Saturday will be 10 degrees below our coldest morning we've had so far this season, with lower 20s a good bet.

Saturday morning is a BIG morning in Richmond, as the Richmond Marathon, half marathon, and 8k are taking place. Make sure you are ready for the chill by dressing in extra layers!

If you have any tomatoes still holding on (anyone?), they need to be harvested.

The record low for Saturday morning is likely safe for another year.  In 1933, it got down to 20 degrees on Nov. 11.

Copyright 2017 WWBT NBC12. All rights reserved.