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