Potter Valley, CA frost dates
Last spring frostApr 8median date
First fall frostNov 6median date
Growing season212 daysfrost-free
Hardiness zone9aZone 9a
How Potter Valley compares
- In 8 years out of 10, the last spring frost in Potter Valley falls between March 11 and April 29, a 49-day window. The first fall frost falls between October 20 and November 24.
- The median last frost is 8 days later than the California median of Mar 31.
- Its 212-day growing season is longer than 39% of the 636 California places with a regular frost season (state median 235 days).
- The last frost is 36 days later than the zone 9a median of Mar 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 9a chart.
- The weather station records an average of 54 nights a year at or below 32°F.
- Compared with Santa Rosa, CA, 110 km away, the last frost here is 42 days later than there and the growing season is 67 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 11 |
| 50% (median) | April 8 |
| 10% (safe for tender plants) | April 29 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 20 |
| 50% (median) | November 6 |
| 90% (late) | November 24 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Potter Valley, CA
Potter Valley, CA frost dates — last frost Apr 8, first frost Nov 6, zone 9a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Jan 14 to Jan 28Transplant outside: Mar 11 to Mar 25
Start indoors: Jan 28 to Feb 11Transplant outside: Apr 22 to May 6
Start indoors: Jan 28 to Feb 11Transplant outside: Apr 22 to May 6
Start indoors: Feb 11 to Feb 25Transplant outside: Apr 15 to Apr 29
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 18 to Apr 1Sow outdoors: Mar 11 to Apr 15Plant for fall: Sep 11 to Oct 9
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 11 to Mar 25Sow outdoors: Mar 11 to Mar 25Plant for fall: Aug 28 to Sep 18
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 25 to Apr 8Plant for fall: Jul 31 to Aug 21
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 18 to Apr 1Plant for fall: Jul 31 to Aug 21
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 25 to Apr 8Plant for fall: Jul 31 to Aug 21
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 29 to May 13Sow outdoors: Apr 29 to May 13
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 15 to Apr 29
Sow outdoors: Feb 25 to Mar 18Plant for fall: Aug 14 to Sep 4
Sow outdoors: Feb 25 to Mar 18Plant for fall: Sep 11 to Oct 2
Sow outdoors: Mar 4 to Apr 15Plant for fall: Sep 25 to Oct 16
Start indoors: Mar 11 to Mar 18Transplant outside: Apr 22 to Apr 29Sow outdoors: Apr 15 to Apr 29Plant for fall: Aug 21 to Sep 4
Start indoors: Mar 11 to Mar 18Sow outdoors: Apr 15 to Apr 29Plant for fall: Aug 28 to Sep 11
Start indoors: Mar 11 to Mar 18Sow outdoors: Apr 15 to Apr 29
Start indoors: Mar 11 to Mar 18Transplant outside: Apr 22 to May 6
Sow outdoors: Mar 18 to Apr 15Plant for fall: Aug 14 to Aug 28
Sow outdoors: Mar 18 to Apr 15Plant for fall: Aug 28 to Sep 11
Sow outdoors: Mar 18 to Apr 8
Sow outdoors: Mar 25 to Apr 22Plant for fall: Aug 28 to Sep 11
Sow outdoors: Mar 25 to Apr 15Plant for fall: Sep 11 to Oct 2
Sow outdoors: Apr 15 to May 6Plant for fall: Aug 21 to Sep 4
Sow outdoors: Apr 15 to Apr 29
Transplant outside: Apr 22 to May 13
Plant for fall: Oct 23 to Nov 27
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Potter Valley, CA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 14 – Jan 28 | Mar 11 – Mar 25 | — | — |
| Peppers | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Eggplant | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Tomatoes | Feb 11 – Feb 25 | Apr 15 – Apr 29 | — | — |
| Lettuce | Feb 11 – Feb 25 | Mar 18 – Apr 1 | Mar 11 – Apr 15 | Sep 11 – Oct 9 |
| Kale | Feb 11 – Feb 25 | Mar 11 – Mar 25 | Mar 11 – Mar 25 | Aug 28 – Sep 18 |
| Broccoli | Feb 11 – Feb 25 | Mar 25 – Apr 8 | — | Jul 31 – Aug 21 |
| Cabbage | Feb 11 – Feb 25 | Mar 18 – Apr 1 | — | Jul 31 – Aug 21 |
| Cauliflower | Feb 11 – Feb 25 | Mar 25 – Apr 8 | — | Jul 31 – Aug 21 |
| Okra | Feb 25 – Mar 11 | Apr 29 – May 13 | Apr 29 – May 13 | — |
| Basil | Feb 25 – Mar 11 | Apr 15 – Apr 29 | — | — |
| Peas | — | — | Feb 25 – Mar 18 | Aug 14 – Sep 4 |
| Spinach | — | — | Feb 25 – Mar 18 | Sep 11 – Oct 2 |
| Radishes | — | — | Mar 4 – Apr 15 | Sep 25 – Oct 16 |
| Cucumbers | Mar 11 – Mar 18 | Apr 22 – Apr 29 | Apr 15 – Apr 29 | Aug 21 – Sep 4 |
| Zucchini & Summer Squash | Mar 11 – Mar 18 | — | Apr 15 – Apr 29 | Aug 28 – Sep 11 |
| Winter Squash & Pumpkins | Mar 11 – Mar 18 | — | Apr 15 – Apr 29 | — |
| Melons & Watermelon | Mar 11 – Mar 18 | Apr 22 – May 6 | — | — |
| Carrots | — | — | Mar 18 – Apr 15 | Aug 14 – Aug 28 |
| Beets | — | — | Mar 18 – Apr 15 | Aug 28 – Sep 11 |
| Potatoes | — | — | Mar 18 – Apr 8 | — |
| Swiss Chard | — | — | Mar 25 – Apr 22 | Aug 28 – Sep 11 |
| Cilantro | — | — | Mar 25 – Apr 15 | Sep 11 – Oct 2 |
| Green Beans | — | — | Apr 15 – May 6 | Aug 21 – Sep 4 |
| Sweet Corn | — | — | Apr 15 – Apr 29 | — |
| Sweet Potatoes | — | Apr 22 – May 13 | — | — |
| Garlic | — | — | — | Oct 23 – Nov 27 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Potter Valley Powerhouse, CA weather station, 6 km away (elevation 1,017 ft (310 m)).
Frost dates near Potter Valley
- Redwood Valley Apr 8 · Nov 6
- Calpella Mar 19 · Nov 20
- Witter Springs Mar 5 · Nov 21
- Willits May 5 · Oct 9
- Upper Lake Mar 5 · Nov 21
- Ukiah Mar 19 · Nov 20
- Talmage Mar 5 · Nov 21
- Nice Apr 10 · Nov 6
- Lakeport Mar 5 · Nov 21
- Elk Creek Apr 5 · Nov 13
Frequently asked questions
When is the last frost in Potter Valley, CA?
The median last spring frost in Potter Valley, CA is April 8. There is still about a 10% chance of frost after April 29, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Potter Valley, CA?
The median first fall frost is November 6, with about a 10% chance of frost before October 20.
How long is the growing season in Potter Valley, CA?
About 212 days between the median last spring frost and first fall frost.
What planting zone is Potter Valley, CA?
Potter Valley, CA is in USDA hardiness zone 9a.