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