Frost Dates: First and last frost dates for leaburg, or

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 June 1. 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 30, so we don't dare plant that early. We wait a few days and by May 12 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° Jan 17 Dec 26 -- -- -- -- -- -- --
Last 20° Feb 11 Jan 30 Jan 21 Jan 12 Jan 2 Dec 15 -- -- --
Last 24° Feb 19 Feb 8 Jan 31 Jan 23 Jan 16 Jan 7 Dec 27 -- --
Last 28° Mar 25 Mar 12 Mar 3 Feb 23 Feb 15 Feb 8 Jan 31 Jan 21 Jan 8
Last 32° May 2 Apr 26 Apr 21 Apr 17 Apr 13 Apr 9 Apr 5 Mar 31 Mar 25
Last 36° Jun 1 May 25 May 20 May 16 May 12 May 9 May 4 Apr 30 Apr 23

How to read these charts for the fall
As your growing season comes to an end, the nightly temperatures for leaburg, or 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 15, and by November 22 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 23.
  2. There is a 50% chance of being hit by a 32° frost starting around November 7
  3. You have a 80% chance of seeing 32° by November 22
  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° Dec 27 Jan 15 -- -- -- -- -- -- --
First 20° Dec 16 Dec 29 Jan 8 Jan 18 Jan 30 -- -- -- --
First 24° Nov 25 Dec 7 Dec 16 Dec 24 Jan 2 Jan 12 Jan 26 -- --
First 28° Nov 4 Nov 13 Nov 20 Nov 25 Nov 30 Dec 6 Dec 11 Dec 18 Dec 27
First 32° Oct 15 Oct 23 Oct 28 Nov 2 Nov 7 Nov 11 Nov 16 Nov 22 Nov 30
First 36° Sep 23 Sep 30 Oct 4 Oct 8 Oct 12 Oct 16 Oct 20 Oct 25 Nov 1

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