Got our first big frost here in northest TN. last night. Calling for more of the same for tonight. 
Your station got a few degrees colder than I did yesterday morning and I’m about 600 miles to your northwest. 
Our winds kept up all night with only breaks in the clouds so I suspect we would have gotten considerably colder with a calm/clear morning.
Had my first frost day of the season in Moab, Utah of all places on vacation. Two mornings in a row 9/21 and 9/22.
That cold air is moving east…expecting our first frost of the season here in NC tommorrow morning.