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