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