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