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 29. 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 26, so we don't dare plant that early. We wait a few days and by March 11 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° | Dec 31 | -- | -- | -- | -- | -- | -- | -- | -- |
Last 20° | Jan 22 | Jan 11 | Dec 31 | -- | -- | -- | -- | -- | -- |
Last 24° | Feb 27 | Feb 14 | Feb 3 | Jan 25 | Jan 15 | Jan 3 | Dec 12 | -- | -- |
Last 28° | Mar 12 | Feb 28 | Feb 19 | Feb 11 | Feb 4 | Jan 28 | Jan 20 | Jan 9 | Dec 20 |
Last 32° | Mar 24 | Mar 15 | Mar 8 | Mar 3 | Feb 25 | Feb 20 | Feb 15 | Feb 8 | Jan 30 |
Last 36° | Mar 29 | Mar 23 | Mar 18 | Mar 14 | Mar 11 | Mar 7 | Mar 3 | Feb 26 | Feb 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° | Jan 6 | -- | -- | -- | -- | -- | -- | -- | -- |
First 20° | Dec 27 | Jan 7 | Jan 17 | -- | -- | -- | -- | -- | -- |
First 24° | Dec 5 | Dec 19 | Dec 30 | Jan 9 | Jan 19 | Feb 2 | -- | -- | -- |
First 28° | Nov 21 | Dec 1 | Dec 8 | Dec 14 | Dec 20 | Dec 25 | Jan 1 | Jan 9 | Jan 25 |
First 32° | Nov 11 | Nov 18 | Nov 23 | Nov 28 | Dec 2 | Dec 6 | Dec 10 | Dec 15 | Dec 22 |
First 36° | Oct 29 | Nov 5 | Nov 9 | Nov 13 | Nov 17 | Nov 20 | Nov 24 | Nov 29 | Dec 5 |
Now that you know your frost dates, use our Garden Planting Calendar for Beaumont 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.