Penn Valley, CA frost dates
Last spring frostApr 10median date
First fall frostNov 13median date
Growing season217 daysfrost-free
Hardiness zone9bZone 9b
How Penn Valley compares
- In 8 years out of 10, the last spring frost in Penn Valley falls between March 17 and April 30, a 44-day window. The first fall frost falls between October 26 and December 1.
- The median last frost is 10 days later than the California median of Mar 31.
- Its 217-day growing season is longer than 43% of the 636 California places with a regular frost season (state median 235 days).
- The last frost is 49 days later than the zone 9b median of Feb 20. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 9b chart.
- The weather station records an average of 61 nights a year at or below 32°F.
- Compared with Yuba City, CA, 39 km away, the last frost here is 58 days later than there and the growing season is 75 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 17 |
| 50% (median) | April 10 |
| 10% (safe for tender plants) | April 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 26 |
| 50% (median) | November 13 |
| 90% (late) | December 1 |
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 Penn Valley, CA
Penn Valley, CA frost dates — last frost Apr 10, first frost Nov 13, zone 9b. whenisthelastfrost.com
Crop
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Start indoors: Jan 16 to Jan 30Transplant outside: Mar 13 to Mar 27
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 24 to May 8
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 24 to May 8
Start indoors: Feb 13 to Feb 27Transplant outside: Apr 17 to May 1
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 20 to Apr 3Sow outdoors: Mar 13 to Apr 17Plant for fall: Sep 18 to Oct 16
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 13 to Mar 27Sow outdoors: Mar 13 to Mar 27Plant for fall: Sep 4 to Sep 25
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 27 to Apr 10Plant for fall: Aug 7 to Aug 28
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 20 to Apr 3Plant for fall: Aug 7 to Aug 28
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 27 to Apr 10Plant for fall: Aug 7 to Aug 28
Start indoors: Feb 27 to Mar 13Transplant outside: May 1 to May 15Sow outdoors: May 1 to May 15
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 17 to May 1
Sow outdoors: Feb 27 to Mar 20Plant for fall: Aug 21 to Sep 11
Sow outdoors: Feb 27 to Mar 20Plant for fall: Sep 18 to Oct 9
Sow outdoors: Mar 6 to Apr 17Plant for fall: Oct 2 to Oct 23
Start indoors: Mar 13 to Mar 20Transplant outside: Apr 24 to May 1Sow outdoors: Apr 17 to May 1Plant for fall: Aug 28 to Sep 11
Start indoors: Mar 13 to Mar 20Sow outdoors: Apr 17 to May 1Plant for fall: Sep 4 to Sep 18
Start indoors: Mar 13 to Mar 20Sow outdoors: Apr 17 to May 1
Start indoors: Mar 13 to Mar 20Transplant outside: Apr 24 to May 8
Sow outdoors: Mar 20 to Apr 17Plant for fall: Aug 21 to Sep 4
Sow outdoors: Mar 20 to Apr 17Plant for fall: Sep 4 to Sep 18
Sow outdoors: Mar 20 to Apr 10
Sow outdoors: Mar 27 to Apr 24Plant for fall: Sep 4 to Sep 18
Sow outdoors: Mar 27 to Apr 17Plant for fall: Sep 18 to Oct 9
Sow outdoors: Apr 17 to May 8Plant for fall: Aug 28 to Sep 11
Sow outdoors: Apr 17 to May 1
Transplant outside: Apr 24 to May 15
Plant for fall: Oct 30 to Dec 4
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Penn Valley, CA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 16 – Jan 30 | Mar 13 – Mar 27 | — | — |
| Peppers | Jan 30 – Feb 13 | Apr 24 – May 8 | — | — |
| Eggplant | Jan 30 – Feb 13 | Apr 24 – May 8 | — | — |
| Tomatoes | Feb 13 – Feb 27 | Apr 17 – May 1 | — | — |
| Lettuce | Feb 13 – Feb 27 | Mar 20 – Apr 3 | Mar 13 – Apr 17 | Sep 18 – Oct 16 |
| Kale | Feb 13 – Feb 27 | Mar 13 – Mar 27 | Mar 13 – Mar 27 | Sep 4 – Sep 25 |
| Broccoli | Feb 13 – Feb 27 | Mar 27 – Apr 10 | — | Aug 7 – Aug 28 |
| Cabbage | Feb 13 – Feb 27 | Mar 20 – Apr 3 | — | Aug 7 – Aug 28 |
| Cauliflower | Feb 13 – Feb 27 | Mar 27 – Apr 10 | — | Aug 7 – Aug 28 |
| Okra | Feb 27 – Mar 13 | May 1 – May 15 | May 1 – May 15 | — |
| Basil | Feb 27 – Mar 13 | Apr 17 – May 1 | — | — |
| Peas | — | — | Feb 27 – Mar 20 | Aug 21 – Sep 11 |
| Spinach | — | — | Feb 27 – Mar 20 | Sep 18 – Oct 9 |
| Radishes | — | — | Mar 6 – Apr 17 | Oct 2 – Oct 23 |
| Cucumbers | Mar 13 – Mar 20 | Apr 24 – May 1 | Apr 17 – May 1 | Aug 28 – Sep 11 |
| Zucchini & Summer Squash | Mar 13 – Mar 20 | — | Apr 17 – May 1 | Sep 4 – Sep 18 |
| Winter Squash & Pumpkins | Mar 13 – Mar 20 | — | Apr 17 – May 1 | — |
| Melons & Watermelon | Mar 13 – Mar 20 | Apr 24 – May 8 | — | — |
| Carrots | — | — | Mar 20 – Apr 17 | Aug 21 – Sep 4 |
| Beets | — | — | Mar 20 – Apr 17 | Sep 4 – Sep 18 |
| Potatoes | — | — | Mar 20 – Apr 10 | — |
| Swiss Chard | — | — | Mar 27 – Apr 24 | Sep 4 – Sep 18 |
| Cilantro | — | — | Mar 27 – Apr 17 | Sep 18 – Oct 9 |
| Green Beans | — | — | Apr 17 – May 8 | Aug 28 – Sep 11 |
| Sweet Corn | — | — | Apr 17 – May 1 | — |
| Sweet Potatoes | — | Apr 24 – May 15 | — | — |
| Garlic | — | — | — | Oct 30 – Dec 4 |
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 Grass Valley #2, CA weather station, 12 km away (elevation 2,402 ft (732 m)).
Frost dates near Penn Valley
- Rough And Ready Apr 10 · Nov 13
- Smartsville Apr 1 · Nov 17
- Grass Valley Apr 10 · Nov 13
- Browns Valley Apr 1 · Nov 17
- Cedar Ridge Apr 10 · Nov 13
- Beale Afb Feb 11 · Nov 30
- Oregon House Apr 1 · Nov 17
- Dobbins Apr 1 · Nov 17
- Chicago Park Apr 3 · Nov 24
- North San Juan Apr 1 · Nov 17
Frequently asked questions
When is the last frost in Penn Valley, CA?
The median last spring frost in Penn Valley, CA is April 10. There is still about a 10% chance of frost after April 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Penn Valley, CA?
The median first fall frost is November 13, with about a 10% chance of frost before October 26.
How long is the growing season in Penn Valley, CA?
About 217 days between the median last spring frost and first fall frost.
What planting zone is Penn Valley, CA?
Penn Valley, CA is in USDA hardiness zone 9b.