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