Frost Dates: First and last frost dates for pearce - sunsites, az
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 16. 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 16, so we don't dare plant that early. We wait a few days and by April 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° | Feb 7 | Jan 25 | Jan 14 | Jan 4 | Dec 23 | Dec 2 | -- | -- | -- |
Last 20° | Feb 28 | Feb 17 | Feb 8 | Jan 31 | Jan 24 | Jan 17 | Jan 9 | Dec 29 | Dec 10 |
Last 24° | Mar 24 | Mar 16 | Mar 11 | Mar 6 | Mar 2 | Feb 25 | Feb 21 | Feb 15 | Feb 7 |
Last 28° | Apr 22 | Apr 13 | Apr 7 | Apr 1 | Mar 27 | Mar 22 | Mar 17 | Mar 11 | Mar 2 |
Last 32° | Apr 30 | Apr 25 | Apr 21 | Apr 17 | Apr 14 | Apr 11 | Apr 7 | Apr 3 | Mar 28 |
Last 36° | May 16 | May 9 | May 5 | May 1 | Apr 28 | Apr 24 | Apr 20 | Apr 16 | Apr 10 |
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 24.
- There is a 50% chance of being hit by a 32° frost starting around November 2
- You have a 80% chance of seeing 32° by November 11
- 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° | Dec 5 | Dec 15 | Dec 22 | Dec 30 | Jan 9 | -- | -- | -- | -- |
First 20° | Nov 16 | Nov 25 | Dec 1 | Dec 6 | Dec 11 | Dec 17 | Dec 23 | Dec 30 | Jan 13 |
First 24° | Nov 6 | Nov 13 | Nov 17 | Nov 22 | Nov 25 | Nov 29 | Dec 3 | Dec 8 | Dec 15 |
First 28° | Oct 29 | Nov 4 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 24 | Nov 29 |
First 32° | Oct 20 | Oct 24 | Oct 28 | Oct 30 | Nov 2 | Nov 5 | Nov 7 | Nov 11 | Nov 15 |
First 36° | Oct 11 | Oct 15 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 8 |
Data is provided by the NOAA National Centers for Environmental Information.