Frost Dates: First and last frost dates for hanford, 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 April 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 March 1, so we don't dare plant that early. We wait a few days and by March 22 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° | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Last 24° | Jan 31 | Jan 18 | Jan 7 | Dec 27 | Dec 14 | -- | -- | -- | -- |
| Last 28° | Feb 26 | Feb 12 | Feb 2 | Jan 25 | Jan 17 | Jan 8 | Dec 30 | Dec 18 | Nov 26 |
| Last 32° | Apr 2 | Mar 20 | Mar 11 | Mar 3 | Feb 24 | Feb 17 | Feb 9 | Jan 31 | Jan 18 |
| Last 36° | Apr 24 | Apr 13 | Apr 4 | Mar 29 | Mar 22 | Mar 16 | Mar 9 | Mar 1 | Feb 17 |
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 13.
- There is a 50% chance of being hit by a 32° frost starting around November 23
- You have a 80% chance of seeing 32° by December 3
- 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° | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| First 24° | Dec 1 | Dec 14 | Dec 24 | Jan 4 | Jan 19 | -- | -- | -- | -- |
| First 28° | Nov 11 | Nov 22 | Nov 30 | Dec 7 | Dec 13 | Dec 20 | Dec 27 | Jan 6 | Jan 23 |
| First 32° | Nov 7 | Nov 13 | Nov 17 | Nov 20 | Nov 23 | Nov 26 | Nov 30 | Dec 3 | Dec 9 |
| First 36° | Oct 22 | Oct 27 | Oct 31 | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 |
Data is provided by the NOAA National Centers for Environmental Information.