Frost dates for Windsor, CA
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
March 2
typical year
Safe to plant
April 2
frost is over in 9 of 10 years
First fall frost
November 20
typical year
Growing season
262 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Feb 2 – 16 | – |
| Spinach | – | Jan 19 – Feb 9 | Sep 25 – Oct 9 |
| Lettuce | – | Feb 2 – 23 | Sep 25 – Oct 9 |
| Radishes | – | Feb 2 – Mar 16 | Oct 9 – 23 |
| Onions | – | Feb 2 – 16 | – |
| Potatoes | – | Feb 9 – 23 | – |
| Carrots | – | Feb 9 – Mar 2 | Aug 28 – Sep 11 |
| Beets | – | Feb 2 – 16 | Sep 11 – 25 |
| Kale | Dec 22 – Jan 5 | Feb 2 – 16 | Sep 11 – 25 |
| Broccoli | Dec 22 – Jan 5 | Feb 16 – Mar 2 | Sep 11 – 25 |
| Cabbage | Dec 8 – 22 | Feb 2 – 16 | Sep 11 – 25 |
| Garlic | – | – | Oct 9 – 30 |
| Warm-season crops | |||
| Tomatoes | Feb 5 – 19 | Apr 2 – 16 | – |
| Peppers | Jan 29 – Feb 12 | Apr 9 – 23 | – |
| Cucumbers | – | Apr 2 – 23 | – |
| Zucchini | – | Apr 2 – 30 | – |
| Pumpkins | – | Apr 2 – 23 | – |
| Green beans | – | Apr 2 – Sep 11 | – |
| Sweet corn | – | Apr 2 – 30 | – |
| Basil | Feb 26 – Mar 12 | Apr 9 – 16 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | April 2 | March 2 | January 27 |
| Fall frost before | November 1 | November 20 | December 10 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around January 23 (February 23 in a late year), and the first one in fall around December 5.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Windsor
Where these dates come from
NOAA weather station SANTA ROSA SONOMA CO AP, CA US (USW00023213), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 3 miles:
95403, 95439, 95492
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.