Last frost date in Glendora, CA
Expect the last frost in Glendora around January 8. Frost after February 18 happens in only one year out of ten. The first fall frost usually arrives about December 28, which leaves 354 frost-free days. An early freeze before December 5 happens one year in ten.
- Safe after (10% risk)
- Feb 18
- Average first frost
- Dec 28
- Frost-free season
- 354 days
- Hard freeze (28°F) ends
- rare
No frost in the next 6 nights
National Weather Service forecast, updated Oct 22, 12:24 UTC
- ThuOct 2252°
- FriOct 2353°
- SatOct 2455°
- SunOct 2557°
- MonOct 2657°
- TueOct 2757°
Planting calendar for Glendora
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 11–Dec 25
OnionsNov 27–Dec 18
CarrotsDec 18–Jan 22
LettuceDec 25–Jan 15
BroccoliDec 11–Dec 25
BeetsDec 11–Jan 22
PeasNov 27–Dec 11
CabbageDec 11–Dec 25
RadishesDec 4–Jan 15
Brussels sproutsDec 25–Jan 8
SpinachNov 27–Dec 18
CilantroDec 25–Jan 15
KaleDec 11–Dec 25
Collard greensDec 11–Dec 25
TurnipsDec 11–Dec 25
DillJan 8–Jan 22
CeleryJan 15–Jan 22
CauliflowerDec 25–Jan 8
LeeksDec 25–Jan 8
Swiss chardDec 25–Jan 22
ParsleyDec 25–Jan 15
Tulip bulbsDec 15–Jan 15
GarlicOct 15–Nov 30
Daffodil bulbsOct 15–Nov 30
StrawberriesDec 11–Dec 25
AsparagusDec 11–Dec 25Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Dec 14 | Jan 8 | Feb 18 | Dec 5 | Dec 28 | Feb 2 |
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 Pomona/fairplex (USC00047050) sits 6.4 miles from the center of Glendora at 999 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 Glendora, CA?
The average last frost date in Glendora is January 8, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after February 18.
When is the first frost in Glendora?
The first frost in fall usually comes around December 28. One year in ten it arrives before December 5.
How long is the growing season in Glendora?
About 354 days between the average last and first frost.
When should I plant tomatoes in Glendora?
Plant tomato seedlings outside from February 15 to March 1. Start seeds indoors six to eight weeks earlier.