Last frost date in Imperial, CA
Expect the last frost in Imperial around January 14. Frost after February 15 happens in only one year out of ten. The first fall frost usually arrives about December 24, which leaves 346 frost-free days. An early freeze before December 2 happens one year in ten.
- Safe after (10% risk)
- Feb 15
- Average first frost
- Dec 24
- Frost-free season
- 346 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 2256°
- FriOct 2357°
- SatOct 2457°
- SunOct 2558°
- MonOct 2658°
- TueOct 2758°
Planting calendar for Imperial
Windows count forward or back from the average frost dates above. Click a crop for dates across California.
TomatoesFeb 15–Mar 1
PumpkinsFeb 15–Mar 1
SunflowersFeb 15–Mar 8
CucumbersFeb 22–Mar 1
CornFeb 15–Mar 1
Sweet potatoesFeb 15–Mar 1
WatermelonFeb 15–Mar 1
Green beansFeb 15–Mar 8
ZucchiniFeb 15–Mar 1
OkraFeb 15–Mar 1
PeppersFeb 15–Mar 1
BasilFeb 15–Mar 1
Butternut squashFeb 15–Mar 1
CantaloupeFeb 15–Mar 1
EggplantFeb 15–Mar 1
PotatoesDec 17–Dec 31
OnionsDec 3–Dec 24
CarrotsDec 24–Jan 28
LettuceDec 31–Jan 21
BroccoliDec 17–Dec 31
BeetsDec 17–Jan 28
PeasDec 3–Dec 17
CabbageDec 17–Dec 31
RadishesDec 10–Jan 21
Brussels sproutsDec 31–Jan 14
SpinachDec 3–Dec 24
CilantroDec 31–Jan 21
KaleDec 17–Dec 31
Collard greensDec 17–Dec 31
TurnipsDec 17–Dec 31
DillJan 14–Jan 28
CeleryJan 21–Jan 28
CauliflowerDec 31–Jan 14
LeeksDec 31–Jan 14
Swiss chardDec 31–Jan 28
ParsleyDec 31–Jan 21
Tulip bulbsDec 15–Jan 15
GarlicOct 15–Nov 30
Daffodil bulbsOct 15–Nov 30
StrawberriesDec 17–Dec 31
AsparagusDec 17–Dec 31Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Dec 18 | Jan 14 | Feb 15 | Dec 2 | Dec 24 | Jan 24 |
| Hard freeze, 28°F | Dec 18 | Jan 8 | Feb 7 | Dec 17 | Jan 5 | Feb 4 |
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 Imperial County Airport (USW00003144) sits 0.5 miles from the center of Imperial at -58 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 Imperial, CA?
The average last frost date in Imperial is January 14, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after February 15.
When is the first frost in Imperial?
The first frost in fall usually comes around December 24. One year in ten it arrives before December 2.
How long is the growing season in Imperial?
About 346 days between the average last and first frost.
When should I plant tomatoes in Imperial?
Plant tomato seedlings outside from February 15 to March 1. Start seeds indoors six to eight weeks earlier.
Nearby in California
- El CentroJan 3
- BrawleyJan 16
- CalexicoJan 3
- CoachellaDec 31
- La QuintaDec 31
- IndioDec 31
- RamonaMar 19
- Palm DesertDec 31
- LakesideJan 6
- Rancho San DiegoJan 6
- Winter GardensJan 6
- El CajonJan 6