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 April 9. 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 March 16, so we don't dare plant that early. We wait a few days and by March 26 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° | Feb 14 | Feb 4 | Jan 28 | Jan 21 | Jan 14 | Jan 5 | Dec 20 | -- | -- |
Last 20° | Feb 27 | Feb 17 | Feb 9 | Feb 2 | Jan 26 | Jan 19 | Jan 10 | Dec 24 | -- |
Last 24° | Mar 8 | Feb 27 | Feb 20 | Feb 14 | Feb 8 | Feb 3 | Jan 28 | Jan 21 | Jan 12 |
Last 28° | Mar 19 | Mar 10 | Mar 4 | Feb 26 | Feb 21 | Feb 16 | Feb 10 | Feb 3 | Jan 25 |
Last 32° | Apr 4 | Mar 28 | Mar 22 | Mar 18 | Mar 14 | Mar 10 | Mar 5 | Feb 28 | Feb 21 |
Last 36° | Apr 9 | Apr 4 | Apr 1 | Mar 29 | Mar 26 | Mar 23 | Mar 20 | Mar 16 | Mar 11 |
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° | Dec 20 | Dec 29 | Jan 4 | Jan 10 | Jan 17 | Jan 26 | -- | -- | -- |
First 20° | Dec 2 | Dec 10 | Dec 17 | Dec 22 | Dec 28 | Jan 3 | Jan 10 | Jan 24 | -- |
First 24° | Nov 18 | Nov 27 | Dec 3 | Dec 9 | Dec 14 | Dec 20 | Dec 25 | Jan 1 | Jan 10 |
First 28° | Nov 11 | Nov 18 | Nov 23 | Nov 27 | Dec 1 | Dec 5 | Dec 9 | Dec 14 | Dec 20 |
First 32° | Nov 1 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 21 | Nov 25 | Nov 29 | Dec 5 |
First 36° | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 24 |
Now that you know your frost dates, use our Garden Planting Calendar for Waxahachie, TX 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.