Frost Dates: First and last frost dates for colebrook, nh
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 July 20. 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 June 10, so we don't dare plant that early. We wait a few days and by June 26 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.
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
Last 16° | Apr 22 | Apr 18 | Apr 15 | Apr 13 | Apr 10 | Apr 8 | Apr 5 | Apr 2 | Mar 29 |
Last 20° | May 1 | Apr 27 | Apr 24 | Apr 22 | Apr 19 | Apr 17 | Apr 14 | Apr 11 | Apr 7 |
Last 24° | May 16 | May 12 | May 9 | May 7 | May 5 | May 3 | Apr 30 | Apr 28 | Apr 24 |
Last 28° | Jun 6 | Jun 1 | May 28 | May 25 | May 22 | May 19 | May 16 | May 13 | May 8 |
Last 32° | Jun 27 | Jun 21 | Jun 16 | Jun 12 | Jun 9 | Jun 5 | Jun 1 | May 28 | May 21 |
Last 36° | Jul 20 | Jul 12 | Jul 6 | Jul 1 | Jun 26 | Jun 21 | Jun 16 | Jun 10 | Jun 2 |
The charts on this page show the probabilities of receiving a certain temperature on a certain day. Some examples that might help:
- You have a small 20% chance of getting 32° by August 26.
- There is a 50% chance of being hit by a 32° frost starting around September 7
- You have a 80% chance of seeing 32° by September 20
- Said another way, you have a 1 in 5 chance at making it to that day without a 32° night.
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
First 16° | Oct 21 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 16 |
First 20° | Oct 2 | Oct 8 | Oct 12 | Oct 16 | Oct 20 | Oct 23 | Oct 27 | Oct 31 | Nov 6 |
First 24° | Sep 26 | Sep 30 | Oct 4 | Oct 7 | Oct 10 | Oct 12 | Oct 15 | Oct 19 | Oct 24 |
First 28° | Sep 16 | Sep 20 | Sep 23 | Sep 26 | Sep 28 | Oct 1 | Oct 4 | Oct 7 | Oct 11 |
First 32° | Aug 20 | Aug 26 | Aug 31 | Sep 4 | Sep 7 | Sep 11 | Sep 15 | Sep 20 | Sep 26 |
First 36° | Aug 10 | Aug 16 | Aug 20 | Aug 24 | Aug 28 | Aug 31 | Sep 4 | Sep 8 | Sep 14 |
Data is provided by the NOAA National Centers for Environmental Information.