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° | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 7 | Dec 9 | Dec 12 | Dec 16 | Dec 21 |
First 20° | Nov 14 | Nov 18 | Nov 22 | Nov 25 | Nov 28 | Dec 1 | Dec 4 | Dec 7 | Dec 12 |
First 24° | Oct 31 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 25 | Nov 30 |
First 28° | Oct 19 | Oct 24 | Oct 27 | Oct 30 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 16 |
First 32° | Oct 5 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 24 | Oct 28 | Nov 2 |
First 36° | Sep 22 | Sep 26 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 10 | Oct 14 | Oct 18 |
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 22. 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 9 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° | Mar 31 | Mar 27 | Mar 24 | Mar 22 | Mar 19 | Mar 17 | Mar 15 | Mar 12 | Mar 8 |
Last 20° | Apr 6 | Apr 2 | Mar 30 | Mar 28 | Mar 26 | Mar 24 | Mar 22 | Mar 19 | Mar 15 |
Last 24° | Apr 16 | Apr 12 | Apr 9 | Apr 6 | Apr 4 | Apr 1 | Mar 29 | Mar 26 | Mar 22 |
Last 28° | Apr 24 | Apr 20 | Apr 18 | Apr 16 | Apr 14 | Apr 12 | Apr 9 | Apr 7 | Apr 3 |
Last 32° | May 6 | May 2 | Apr 29 | Apr 26 | Apr 24 | Apr 22 | Apr 19 | Apr 16 | Apr 12 |
Last 36° | May 22 | May 18 | May 14 | May 12 | May 9 | May 7 | May 4 | May 1 | Apr 26 |
Now that you know your frost dates, use our Garden Planting Calendar for Amherst, New York 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.