Last frost date in San Tan Valley, AZ
The average last frost in San Tan Valley is February 1. By February 27 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about December 11, which leaves 315 frost-free days. An early freeze before November 23 happens one year in ten.
- Safe after (10% risk)
- Feb 27
- Average first frost
- Dec 11
- Frost-free season
- 315 days
- Hard freeze (28°F) ends
- Jan 8
No frost in the next 6 nights
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2260°
- FriOct 2358°
- SatOct 2457°
- SunOct 2556°
- MonOct 2659°
- TueOct 2760°
Planting calendar for San Tan Valley
Windows count forward or back from the average frost dates above. Click a crop for dates across Arizona.
TomatoesFeb 15–Mar 1
PumpkinsFeb 15–Mar 1
SunflowersFeb 15–Mar 8
CucumbersFeb 22–Mar 1
CornFeb 15–Mar 1
Sweet potatoesFeb 22–Mar 8
WatermelonFeb 15–Mar 1
Green beansFeb 15–Mar 8
ZucchiniFeb 15–Mar 1
OkraFeb 22–Mar 8
PeppersFeb 15–Mar 1
BasilFeb 15–Mar 1
Butternut squashFeb 15–Mar 1
CantaloupeFeb 15–Mar 1
EggplantFeb 15–Mar 1
PotatoesJan 4–Jan 18
OnionsDec 21–Jan 11
CarrotsJan 11–Feb 15
LettuceJan 18–Feb 8
BroccoliJan 4–Jan 18
BeetsJan 4–Feb 15
PeasDec 21–Jan 4
CabbageJan 4–Jan 18
RadishesDec 28–Feb 8
Brussels sproutsJan 18–Feb 1
SpinachDec 21–Jan 11
CilantroJan 18–Feb 8
KaleJan 4–Jan 18
Collard greensJan 4–Jan 18
TurnipsJan 4–Jan 18
DillFeb 1–Feb 15
CeleryFeb 8–Feb 15
CauliflowerJan 18–Feb 1
LeeksJan 18–Feb 1
Swiss chardJan 18–Feb 15
ParsleyJan 18–Feb 8
Tulip bulbsDec 15–Jan 15
GarlicOct 15–Nov 30
Daffodil bulbsOct 15–Nov 30
StrawberriesJan 4–Jan 18
AsparagusJan 4–Jan 18Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Jan 2 | Feb 1 | Feb 27 | Nov 23 | Dec 11 | Jan 1 |
| Hard freeze, 28°F | Dec 15 | Jan 8 | Feb 11 | Dec 4 | Dec 26 | Jan 29 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Chandler Heights (USC00021514) sits 7.1 miles from the center of San Tan Valley at 1,425 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in San Tan Valley, AZ?
The average last frost date in San Tan Valley is February 1, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after February 27.
When is the first frost in San Tan Valley?
The first frost in fall usually comes around December 11. One year in ten it arrives before November 23.
How long is the growing season in San Tan Valley?
About 315 days between the average last and first frost.
When should I plant tomatoes in San Tan Valley?
Plant tomato seedlings outside from February 15 to March 1. Start seeds indoors six to eight weeks earlier.
Nearby in Arizona
- Queen CreekFeb 1
- FlorenceJan 30
- GilbertFeb 1
- ChandlerFeb 13
- Casa GrandeFeb 5
- TempeFeb 13
- MaricopaFeb 23
- ScottsdaleJan 27
- PhoenixJan 8
- GlendaleJan 20
- AvondaleJan 14
- GoodyearJan 14