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 2, so we don't dare plant that early. We wait a few days and by April 23 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° | -- | -- | -- | -- | -- | -- | -- | -- | -- |
Last 20° | Dec 26 | -- | -- | -- | -- | -- | -- | -- | -- |
Last 24° | Jan 31 | Jan 19 | Jan 8 | Dec 28 | Dec 9 | -- | -- | -- | -- |
Last 28° | Mar 29 | Mar 12 | Feb 27 | Feb 16 | Feb 5 | Jan 25 | Jan 13 | Dec 29 | Nov 30 |
Last 32° | May 5 | Apr 23 | Apr 14 | Apr 7 | Mar 31 | Mar 24 | Mar 17 | Mar 8 | Feb 24 |
Last 36° | May 24 | May 14 | May 6 | Apr 29 | Apr 23 | Apr 16 | Apr 10 | Apr 2 | Mar 22 |
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° | -- | -- | -- | -- | -- | -- | -- | -- | -- |
First 20° | Dec 22 | -- | -- | -- | -- | -- | -- | -- | -- |
First 24° | Dec 14 | Dec 25 | Jan 3 | Jan 14 | -- | -- | -- | -- | -- |
First 28° | Nov 21 | Nov 30 | Dec 6 | Dec 12 | Dec 17 | Dec 23 | Dec 30 | Jan 7 | -- |
First 32° | Nov 10 | Nov 15 | Nov 19 | Nov 22 | Nov 25 | Nov 28 | Dec 1 | Dec 5 | Dec 10 |
First 36° | Oct 25 | Oct 31 | Nov 4 | Nov 8 | Nov 12 | Nov 15 | Nov 19 | Nov 23 | Nov 29 |
Now that you know your frost dates, use our Garden Planting Calendar for Auberry, CA 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.