Last frost date in Windsor, CA
In Windsor, the last spring frost comes around March 2 in an average year. Wait until April 2 if you want 90% odds of no more frost. The first fall frost usually arrives about November 20, which leaves 262 frost-free days. An early freeze before November 1 happens one year in ten.
- Safe after (10% risk)
- Apr 2
- Average first frost
- Nov 20
- Frost-free season
- 262 days
- Hard freeze (28°F) ends
- Jan 23
No frost in the next 6 nights
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2242°
- FriOct 2338°
- SatOct 2441°
- SunOct 2543°
- MonOct 2642°
- TueOct 2742°
Planting calendar for Windsor
Windows count forward or back from the average frost dates above. Click a crop for dates across California.
TomatoesMar 9–Mar 23
PumpkinsMar 16–Mar 30
SunflowersMar 2–Mar 23
CucumbersMar 16–Mar 23
CornMar 9–Mar 23
Sweet potatoesMar 23–Apr 6
WatermelonMar 16–Mar 30
Green beansMar 9–Mar 30
ZucchiniMar 9–Mar 23
OkraMar 23–Apr 6
PeppersMar 16–Mar 30
BasilMar 9–Mar 23
Butternut squashMar 9–Mar 23
CantaloupeMar 16–Mar 30
EggplantMar 16–Mar 30
PotatoesFeb 2–Feb 16
OnionsJan 19–Feb 9
CarrotsFeb 9–Mar 16
LettuceFeb 16–Mar 9
BroccoliFeb 2–Feb 16
BeetsFeb 2–Mar 16
PeasJan 19–Feb 2
CabbageFeb 2–Feb 16
RadishesJan 26–Mar 9
Brussels sproutsFeb 16–Mar 2
SpinachJan 19–Feb 9
CilantroFeb 16–Mar 9
KaleFeb 2–Feb 16
Collard greensFeb 2–Feb 16
TurnipsFeb 2–Feb 16
DillMar 2–Mar 16
CeleryMar 9–Mar 16
CauliflowerFeb 16–Mar 2
LeeksFeb 16–Mar 2
Swiss chardFeb 16–Mar 16
ParsleyFeb 16–Mar 9
Tulip bulbsNov 6–Dec 11
GarlicOct 15–Nov 30
Daffodil bulbsOct 15–Nov 30
StrawberriesFeb 2–Feb 16
AsparagusFeb 2–Feb 16Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Jan 27 | Mar 2 | Apr 2 | Nov 1 | Nov 20 | Dec 10 |
| Hard freeze, 28°F | Dec 20 | Jan 23 | Feb 23 | Nov 15 | Dec 5 | Jan 7 |
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 Santa Rosa Sonoma County Airport (USW00023213) sits 2.6 miles from the center of Windsor at 114 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 Windsor, CA?
The average last frost date in Windsor is March 2, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 2.
When is the first frost in Windsor?
The first frost in fall usually comes around November 20. One year in ten it arrives before November 1.
How long is the growing season in Windsor?
About 262 days between the average last and first frost.
When should I plant tomatoes in Windsor?
Plant tomato seedlings outside from March 9 to March 23. Start seeds indoors six to eight weeks earlier.
Nearby in California
- Santa RosaFeb 25
- Rohnert ParkFeb 25
- PetalumaFeb 28
- NapaFeb 12
- NovatoJan 11
- American CanyonMar 5
- San RafaelJan 11
- VallejoJan 17
- HerculesJan 17
- FairfieldJan 15
- VacavilleFeb 18
- San PabloJan 4