Frost Dates: First and last frost dates for mc dermitt, or
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 27. 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 19, so we don't dare plant that early. We wait a few days and by July 4 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° | May 11 | Apr 28 | Apr 19 | Apr 12 | Apr 4 | Mar 28 | Mar 21 | Mar 12 | Feb 27 |
Last 20° | May 19 | May 10 | May 4 | Apr 29 | Apr 24 | Apr 19 | Apr 14 | Apr 8 | Mar 30 |
Last 24° | May 30 | May 23 | May 18 | May 13 | May 9 | May 5 | May 1 | Apr 25 | Apr 18 |
Last 28° | Jun 30 | Jun 21 | Jun 14 | Jun 9 | Jun 3 | May 29 | May 24 | May 17 | May 8 |
Last 32° | Jul 18 | Jul 8 | Jul 2 | Jun 26 | Jun 20 | Jun 15 | Jun 9 | Jun 2 | May 24 |
Last 36° | Jul 27 | Jul 19 | Jul 14 | Jul 9 | Jul 4 | Jun 30 | Jun 25 | Jun 19 | Jun 11 |
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 22.
- There is a 50% chance of being hit by a 32° frost starting around September 6
- You have a 80% chance of seeing 32° by September 21
- 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° | Sep 28 | Oct 5 | Oct 10 | Oct 14 | Oct 18 | Oct 22 | Oct 26 | Oct 31 | Nov 7 |
First 20° | Sep 17 | Sep 24 | Sep 29 | Oct 3 | Oct 8 | Oct 12 | Oct 16 | Oct 21 | Oct 28 |
First 24° | Sep 7 | Sep 14 | Sep 18 | Sep 22 | Sep 26 | Sep 30 | Oct 4 | Oct 9 | Oct 16 |
First 28° | Aug 28 | Sep 4 | Sep 9 | Sep 13 | Sep 17 | Sep 21 | Sep 25 | Sep 30 | Oct 7 |
First 32° | Aug 15 | Aug 22 | Aug 28 | Sep 2 | Sep 6 | Sep 10 | Sep 15 | Sep 21 | Sep 28 |
First 36° | Aug 3 | Aug 9 | Aug 13 | Aug 17 | Aug 21 | Aug 24 | Aug 28 | Sep 1 | Sep 7 |
Data is provided by the NOAA National Centers for Environmental Information.