Frost Dates: First and last frost dates for pendleton br, 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 August 6. 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 July 13, so we don't dare plant that early. We wait a few days and by July 23 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° Apr 23 Apr 14 Apr 7 Apr 2 Mar 27 Mar 22 Mar 16 Mar 9 Feb 28
Last 20° May 26 May 16 May 9 May 3 Apr 27 Apr 21 Apr 15 Apr 8 Mar 29
Last 24° Jun 4 May 28 May 23 May 19 May 15 May 11 May 6 May 1 Apr 24
Last 28° Jul 8 Jun 29 Jun 23 Jun 17 Jun 12 Jun 7 Jun 2 May 27 May 18
Last 32° Jul 30 Jul 23 Jul 19 Jul 15 Jul 11 Jul 7 Jul 3 Jun 28 Jun 22
Last 36° Aug 6 Aug 1 Jul 29 Jul 26 Jul 23 Jul 20 Jul 17 Jul 13 Jul 8

How to read these charts for the fall
As your growing season comes to an end, the nightly temperatures for pendleton br, 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 August 3, and by August 29 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 August 8.
  2. There is a 50% chance of being hit by a 32° frost starting around August 18
  3. You have a 80% chance of seeing 32° by August 29
  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° Sep 26 Oct 3 Oct 8 Oct 12 Oct 16 Oct 20 Oct 25 Oct 30 Nov 5
First 20° Sep 17 Sep 23 Sep 27 Sep 30 Oct 3 Oct 6 Oct 10 Oct 14 Oct 19
First 24° Aug 29 Sep 3 Sep 7 Sep 10 Sep 13 Sep 16 Sep 19 Sep 23 Sep 28
First 28° Aug 16 Aug 22 Aug 26 Aug 30 Sep 2 Sep 6 Sep 9 Sep 14 Sep 19
First 32° Aug 3 Aug 8 Aug 12 Aug 15 Aug 18 Aug 21 Aug 25 Aug 29 Sep 3
First 36° Jul 31 Aug 1 Aug 3 Aug 4 Aug 6 Aug 7 Aug 9 Aug 11 Aug 13

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