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