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