Frost Dates: First and last frost dates for priest valley, ca
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 July 6. 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 27, so we don't dare plant that early. We wait a few days and by June 12 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° | Feb 19 | Feb 3 | Jan 22 | Jan 11 | Dec 30 | Dec 16 | Nov 21 | -- | -- |
Last 20° | Mar 15 | Feb 28 | Feb 17 | Feb 8 | Jan 30 | Jan 21 | Jan 11 | Dec 30 | Dec 12 |
Last 24° | Apr 23 | Apr 7 | Mar 26 | Mar 17 | Mar 8 | Feb 26 | Feb 17 | Feb 5 | Jan 20 |
Last 28° | May 26 | May 16 | May 9 | May 3 | Apr 28 | Apr 22 | Apr 16 | Apr 9 | Mar 30 |
Last 32° | Jun 11 | Jun 4 | May 30 | May 26 | May 22 | May 18 | May 13 | May 8 | May 1 |
Last 36° | Jul 6 | Jun 28 | Jun 22 | Jun 17 | Jun 12 | Jun 7 | Jun 2 | May 27 | May 19 |
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 October 2.
- There is a 50% chance of being hit by a 32° frost starting around October 13
- You have a 80% chance of seeing 32° by October 25
- 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° | Nov 24 | Dec 4 | Dec 13 | Dec 20 | Dec 28 | Jan 7 | Jan 24 | -- | -- |
First 20° | Nov 5 | Nov 16 | Nov 23 | Nov 30 | Dec 6 | Dec 12 | Dec 19 | Dec 27 | Jan 8 |
First 24° | Oct 27 | Nov 3 | Nov 8 | Nov 12 | Nov 16 | Nov 20 | Nov 24 | Nov 29 | Dec 6 |
First 28° | Oct 9 | Oct 16 | Oct 21 | Oct 25 | Oct 29 | Nov 1 | Nov 5 | Nov 10 | Nov 17 |
First 32° | Sep 26 | Oct 2 | Oct 6 | Oct 10 | Oct 13 | Oct 17 | Oct 20 | Oct 25 | Oct 31 |
First 36° | Sep 9 | Sep 16 | Sep 21 | Sep 25 | Sep 29 | Oct 3 | Oct 7 | Oct 12 | Oct 19 |
Data is provided by the NOAA National Centers for Environmental Information.