Frost Dates: First and last frost dates for Phantom Ranch, AZ
ℹ️ How to read these charts for the spring
As spring unfolds, the risk of frost gradually decreases each day until your tender plants are finally safe. The probabilities shown in the chart help you make smart decisions about when to plant.
While frost typically forms at 32°F, tender plants can be damaged even when temperatures are slightly higher. Air temperatures are often measured several feet above the ground, but temperatures at plant level can be several degrees colder. Protected areas like porches help by blocking radiational cooling. Given these variables, we consider 36°F the "caution zone" for frost-sensitive plants.
Key dates for your spring planting:
- By May 1, you have a 90% chance of being frost-free — this is your "safe date" for planting tender crops
- Around April 9, there's a 50/50 chance of frost — check weather forecasts carefully if planting now
- Before March 26, there's still an 80% risk of frost — too early for tomatoes and other tender plants unless you're prepared to protect them
If the 10-day forecast shows no temperatures below 40°F, you might safely plant earlier than the above dates suggest. Many gardeners watch for this weather window to get a head start on the growing season.
| Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| Last 16° | Jan 15 | Dec 27 | -- | -- | -- | -- | -- | -- | -- |
| Last 20° | Feb 5 | Jan 21 | Jan 6 | -- | -- | -- | -- | -- | -- |
| Last 24° | Feb 27 | Feb 9 | Jan 26 | Jan 11 | Dec 24 | -- | -- | -- | -- |
| Last 28° | Mar 19 | Mar 5 | Feb 23 | Feb 15 | Feb 6 | Jan 29 | Jan 20 | Jan 9 | Dec 23 |
| Last 32° | Apr 20 | Apr 8 | Mar 30 | Mar 23 | Mar 16 | Mar 9 | Mar 2 | Feb 21 | Feb 9 |
| Last 36° | May 1 | Apr 23 | Apr 18 | Apr 13 | Apr 9 | Apr 5 | Mar 31 | Mar 26 | Mar 18 |
ℹ️ How to read these charts for the fall
As summer ends in Phantom Ranch, AZ, nighttime temperatures begin to drop, and your risk of frost increases with each passing day. Knowing when to expect frost helps you harvest sensitive crops and extend your growing season with protection methods.
The chart below shows the probability of experiencing specific temperatures on various dates. Here's what this means for your garden:
These probabilities help you time your end-of-season harvests and know when to apply protective measures like row covers, cloches, or cold frames to extend your harvest.
| Temperature | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| First 16° | Dec 17 | Jan 8 | -- | -- | -- | -- | -- | -- | -- |
| First 20° | Dec 15 | Jan 2 | Jan 22 | -- | -- | -- | -- | -- | -- |
| First 24° | Nov 22 | Dec 6 | Dec 17 | Dec 29 | Jan 14 | -- | -- | -- | -- |
| First 28° | Nov 13 | Nov 22 | Nov 29 | Dec 5 | Dec 11 | Dec 17 | Dec 24 | Jan 1 | Jan 17 |
| First 32° | Oct 31 | Nov 7 | Nov 12 | Nov 17 | Nov 21 | Nov 25 | Nov 30 | Dec 5 | Dec 12 |
| First 36° | Oct 26 | Oct 31 | Nov 4 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 22 | Nov 27 |
📍 Frost Dates for other nearby locations
- Tucson, AZ 14.9 mi
- Tucson Wfo, AZ 21.1 mi
- Tucson Camp Ave Exp, AZ 24.3 mi
- Tumacacori Nm, AZ 29.4 mi
- Canelo, AZ 34.6 mi
- Nogales, AZ 34.7 mi
- Anvil Rch, AZ 37.0 mi
- Cascabel, AZ 40.0 mi
- Oracle, AZ 46.3 mi
- Kitt Peak, AZ 51.7 mi
Or enter a new zipcode:
Data is provided by the NOAA National Centers for Environmental Information.