Frost Dates: First and last frost dates for Orick Prairie Creek Pk, 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 June 21. 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 13, so we don't dare plant that early. We wait a few days and by May 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° | Dec 31 | -- | -- | -- | -- | -- | -- | -- | -- |
| Last 24° | Jan 25 | Jan 8 | Dec 24 | Nov 30 | -- | -- | -- | -- | -- |
| Last 28° | Apr 12 | Mar 27 | Mar 15 | Mar 4 | Feb 23 | Feb 13 | Feb 2 | Jan 20 | Dec 31 |
| Last 32° | May 31 | May 21 | May 14 | May 8 | May 2 | Apr 26 | Apr 20 | Apr 13 | Apr 3 |
| Last 36° | Jun 21 | Jun 13 | Jun 7 | Jun 2 | May 28 | May 24 | May 19 | May 13 | May 5 |
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 18.
- There is a 50% chance of being hit by a 32° frost starting around November 3
- You have a 80% chance of seeing 32° by November 18
- 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° | Jan 9 | -- | -- | -- | -- | -- | -- | -- | -- |
| First 24° | Dec 9 | Dec 29 | Jan 19 | -- | -- | -- | -- | -- | -- |
| First 28° | Nov 5 | Nov 18 | Nov 27 | Dec 6 | Dec 13 | Dec 21 | Dec 30 | Jan 9 | Jan 25 |
| First 32° | Oct 10 | Oct 18 | Oct 24 | Oct 29 | Nov 3 | Nov 7 | Nov 12 | Nov 18 | Nov 26 |
| First 36° | Sep 5 | Sep 14 | Sep 21 | Sep 26 | Oct 1 | Oct 7 | Oct 12 | Oct 19 | Oct 27 |
Data is provided by the NOAA National Centers for Environmental Information.