Last frost date in Walnut Creek, CA
The average last frost in Walnut Creek is January 7. By February 1 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about December 19, which leaves 346 frost-free days. An early freeze before December 1 happens one year in ten.
- Safe after (10% risk)
- Feb 1
- Average first frost
- Dec 19
- Frost-free season
- 346 days
- Hard freeze (28°F) ends
- Dec 31
No frost in the next 6 nights
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2250°
- FriOct 2346°
- SatOct 2447°
- SunOct 2549°
- MonOct 2648°
- TueOct 2749°
Planting calendar for Walnut Creek
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 10–Dec 24
OnionsNov 26–Dec 17
CarrotsDec 17–Jan 21
LettuceDec 24–Jan 14
BroccoliDec 10–Dec 24
BeetsDec 10–Jan 21
PeasNov 26–Dec 10
CabbageDec 10–Dec 24
RadishesDec 3–Jan 14
Brussels sproutsDec 24–Jan 7
SpinachNov 26–Dec 17
CilantroDec 24–Jan 14
KaleDec 10–Dec 24
Collard greensDec 10–Dec 24
TurnipsDec 10–Dec 24
DillJan 7–Jan 21
CeleryJan 14–Jan 21
CauliflowerDec 24–Jan 7
LeeksDec 24–Jan 7
Swiss chardDec 24–Jan 21
ParsleyDec 24–Jan 14
Tulip bulbsDec 15–Jan 15
GarlicOct 15–Nov 30
Daffodil bulbsOct 15–Nov 30
StrawberriesDec 10–Dec 24
AsparagusDec 10–Dec 24Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Dec 19 | Jan 7 | Feb 1 | Dec 1 | Dec 19 | Jan 12 |
| Hard freeze, 28°F | Dec 14 | Dec 31 | Jan 20 | Dec 10 | Dec 29 | Jan 14 |
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 Concord Wwtp (USC00041967) sits 5.8 miles from the center of Walnut Creek at 40 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 Walnut Creek, CA?
The average last frost date in Walnut Creek is January 7, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after February 1.
When is the first frost in Walnut Creek?
The first frost in fall usually comes around December 19. One year in ten it arrives before December 1.
How long is the growing season in Walnut Creek?
About 346 days between the average last and first frost.
When should I plant tomatoes in Walnut Creek?
Plant tomato seedlings outside from February 15 to March 1. Start seeds indoors six to eight weeks earlier.