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