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 24. 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 26, so we don't dare plant that early. We wait a few days and by May 7 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. If conditions change and a surprise frost does threaten, there's always things you can do to protect plants from frost.
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
Last 16° | Apr 4 | Mar 30 | Mar 26 | Mar 23 | Mar 20 | Mar 16 | Mar 13 | Mar 9 | Mar 4 |
Last 20° | Apr 13 | Apr 8 | Apr 4 | Mar 31 | Mar 28 | Mar 25 | Mar 21 | Mar 17 | Mar 12 |
Last 24° | Apr 20 | Apr 16 | Apr 12 | Apr 10 | Apr 7 | Apr 5 | Apr 2 | Mar 30 | Mar 26 |
Last 28° | May 7 | May 2 | Apr 28 | Apr 24 | Apr 21 | Apr 17 | Apr 14 | Apr 10 | Apr 4 |
Last 32° | May 11 | May 7 | May 4 | May 1 | Apr 28 | Apr 26 | Apr 23 | Apr 20 | Apr 15 |
Last 36° | May 24 | May 18 | May 14 | May 10 | May 7 | May 3 | Apr 30 | Apr 26 | Apr 20 |
The charts on this page show the probabilities of receiving a certain temperature on a certain day. Some examples that might help:
Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
---|---|---|---|---|---|---|---|---|---|
First 16° | Oct 26 | Nov 2 | Nov 6 | Nov 10 | Nov 14 | Nov 18 | Nov 22 | Nov 26 | Dec 3 |
First 20° | Oct 16 | Oct 22 | Oct 27 | Oct 31 | Nov 4 | Nov 8 | Nov 12 | Nov 17 | Nov 24 |
First 24° | Oct 8 | Oct 14 | Oct 18 | Oct 21 | Oct 25 | Oct 28 | Nov 1 | Nov 5 | Nov 11 |
First 28° | Sep 28 | Oct 3 | Oct 7 | Oct 10 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 27 |
First 32° | Sep 16 | Sep 22 | Sep 26 | Sep 29 | Oct 2 | Oct 5 | Oct 9 | Oct 13 | Oct 18 |
First 36° | Sep 12 | Sep 16 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Sep 29 | Oct 2 | Oct 6 |
Now that you know your frost dates, use our Garden Planting Calendar for West Point, NE to know when to sow and transplant your various vegetable plants!
Data is provided by the NOAA National Centers for Environmental Information. Photography by Garden.org member TBGDN.