Frost dates for Napa, 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 5
typical year
Safe to plant
April 16
frost is over in 9 of 10 years
First fall frost
November 21
typical year
Growing season
256 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 5 – 19 | – |
| Spinach | – | Jan 22 – Feb 12 | Sep 26 – Oct 10 |
| Lettuce | – | Feb 5 – 26 | Sep 26 – Oct 10 |
| Radishes | – | Feb 5 – Mar 19 | Oct 10 – 24 |
| Onions | – | Feb 5 – 19 | – |
| Potatoes | – | Feb 12 – 26 | – |
| Carrots | – | Feb 12 – Mar 5 | Aug 29 – Sep 12 |
| Beets | – | Feb 5 – 19 | Sep 12 – 26 |
| Kale | Dec 25 – Jan 8 | Feb 5 – 19 | Sep 12 – 26 |
| Broccoli | Dec 25 – Jan 8 | Feb 19 – Mar 5 | Sep 12 – 26 |
| Cabbage | Dec 11 – 25 | Feb 5 – 19 | Sep 12 – 26 |
| Garlic | – | – | Oct 10 – 31 |
| Warm-season crops | |||
| Tomatoes | Feb 19 – Mar 5 | Apr 16 – 30 | – |
| Peppers | Feb 12 – 26 | Apr 23 – May 7 | – |
| Cucumbers | – | Apr 16 – May 7 | – |
| Zucchini | – | Apr 16 – May 14 | – |
| Pumpkins | – | Apr 16 – May 7 | – |
| Green beans | – | Apr 16 – Sep 12 | – |
| Sweet corn | – | Apr 16 – May 14 | – |
| Basil | Mar 12 – 26 | Apr 23 – 30 | – |
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 16 | March 5 | January 26 |
| Fall frost before | November 3 | November 21 | December 13 |
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 28 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 2 towns.
Napa, American Canyon
Where these dates come from
NOAA weather station NAPA CO AP, CA US (USW00093227), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 4 miles:
94503, 94559
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.