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