Frost Dates: First and last frost dates for Duncan, OK

How to read these charts for the spring
As the growing season approaches, the days get longer, the weather begins to warm up, and the nights start being less cold. You're still getting frost, but the chance of nightly frosts gets less and less with each passing day. Eventually, the frost stops, and this is when your tender plants are fully safe. So, how do you plan for this? The probabilities on this page help you assess your risk of frost on any given day.

What's a safe temperature for tender plants? When the nightly temperature falls, frost can form, even above 32°, because the air is colder high above the ground and the frost can form up there and then fall down onto your garden and do some damage, even if it's 36° on the ground. So many factors come into play, including wind, concrete, houses, trees and other structures, etc etc etc. Because of all this, you might want to consider 36° as "the danger zone".

In your average springtime, you have a 90% chance that there will be no 36° nights by April 16. In other words, you can pretty much count on being safe from frost by that day. But we want to get those tomatoes in the ground as soon as possible, right? We see that there's still an 80% chance of 36° on April 1, so we don't dare plant that early. We wait a few days and by April 7 we are at the 50/50 point. At this point, we are close and we can start watching the weather forecast. If the upcoming week's forecast doesn't show below 40°, then it's probably okay to risk planting out your plants.

In the Spring
Temperature 10% 20% 30% 40% 50% 60% 70% 80% 90%
Last 16° Mar 3 Feb 21 Feb 14 Feb 8 Feb 2 Jan 27 Jan 20 Jan 11 Dec 26
Last 20° Mar 11 Mar 3 Feb 24 Feb 19 Feb 14 Feb 9 Feb 4 Jan 29 Jan 20
Last 24° Mar 22 Mar 14 Mar 8 Mar 4 Feb 27 Feb 23 Feb 18 Feb 12 Feb 4
Last 28° Apr 2 Mar 27 Mar 22 Mar 18 Mar 14 Mar 10 Mar 6 Mar 1 Feb 22
Last 32° Apr 12 Apr 6 Apr 2 Mar 30 Mar 26 Mar 23 Mar 20 Mar 16 Mar 10
Last 36° Apr 16 Apr 13 Apr 10 Apr 9 Apr 7 Apr 5 Apr 3 Apr 1 Mar 29

How to read these charts for the fall
As your growing season comes to an end, the nightly temperatures for Duncan, OK start to go down, and therefore every day that goes by increases the chance that you'll get frost. Your risk of frost really begins around October 23, and by November 19 you're almost certain to have received at least one frost event.

The charts on this page show the probabilities of receiving a certain temperature on a certain day. Some examples that might help:

  1. You have a small 20% chance of getting 32° by October 29.
  2. There is a 50% chance of being hit by a 32° frost starting around November 9
  3. You have a 80% chance of seeing 32° by November 19
  4. Said another way, you have a 1 in 5 chance at making it to that day without a 32° night.
In the Fall
Temperature 10% 20% 30% 40% 50% 60% 70% 80% 90%
First 16° Nov 21 Dec 3 Dec 11 Dec 19 Dec 26 Jan 2 Jan 10 Jan 20 Feb 8
First 20° Nov 15 Nov 24 Nov 30 Dec 5 Dec 10 Dec 15 Dec 20 Dec 26 Jan 4
First 24° Nov 11 Nov 18 Nov 23 Nov 27 Dec 1 Dec 5 Dec 9 Dec 14 Dec 21
First 28° Nov 3 Nov 9 Nov 13 Nov 17 Nov 20 Nov 23 Nov 27 Dec 2 Dec 8
First 32° Oct 23 Oct 29 Nov 2 Nov 5 Nov 9 Nov 12 Nov 15 Nov 19 Nov 25
First 36° Oct 16 Oct 21 Oct 24 Oct 27 Oct 30 Nov 2 Nov 5 Nov 8 Nov 13

Frost Dates for other nearby locations
  • Waurika, OK
  • Walters, OK
  • Lindsay, OK
  • Lawton, OK
  • Chickasha, OK
  • Healdton, OK
  • Anadarko, OK
  • Blanchard, OK
  • Chattanooga, OK
  • Pauls Valley, OK

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    • Data is provided by the NOAA National Centers for Environmental Information.