San Gregorio, CA frost dates
Last spring frostMar 2median date
First fall frostNov 25median date
Growing season268 daysfrost-free
Hardiness zone9bZone 9b
How San Gregorio compares
- In 8 years out of 10, the last spring frost in San Gregorio falls between December 31 and April 15, a 105-day window. The first fall frost falls between November 1 and January 1.
- The median last frost is 29 days earlier than the California median of Mar 31.
- Its 268-day growing season is longer than 67% of the 636 California places with a regular frost season (state median 235 days).
- The last frost is 10 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 16 nights a year at or below 32°F.
- Nearby Redwood City, CA, 17 km away, gets only light, occasional frost, a reminder of how much elevation and distance from the coast matter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 31 |
| 50% (median) | March 2 |
| 10% (safe for tender plants) | April 15 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 1 |
| 50% (median) | November 25 |
| 90% (late) | January 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 San Gregorio, CA
San Gregorio, CA frost dates — last frost Mar 2, first frost Nov 25, zone 9b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Dec 8 to Dec 22Transplant outside: Feb 2 to Feb 16
Start indoors: Dec 22 to Jan 5Start indoors: Dec 22 to Jan 5Transplant outside: Mar 16 to Mar 30
Start indoors: Dec 22 to Jan 5Start indoors: Dec 22 to Jan 5Transplant outside: Mar 16 to Mar 30
Start indoors: Jan 5 to Jan 19Transplant outside: Mar 9 to Mar 23
Start indoors: Jan 5 to Jan 19Transplant outside: Feb 9 to Feb 23Sow outdoors: Feb 2 to Mar 9Plant for fall: Sep 30 to Oct 28
Start indoors: Jan 5 to Jan 19Transplant outside: Feb 2 to Feb 16Sow outdoors: Feb 2 to Feb 16Plant for fall: Sep 16 to Oct 7
Start indoors: Jan 5 to Jan 19Transplant outside: Feb 16 to Mar 2Plant for fall: Aug 19 to Sep 9
Start indoors: Jan 5 to Jan 19Transplant outside: Feb 9 to Feb 23Plant for fall: Aug 19 to Sep 9
Start indoors: Jan 5 to Jan 19Transplant outside: Feb 16 to Mar 2Plant for fall: Aug 19 to Sep 9
Start indoors: Jan 19 to Feb 2Transplant outside: Mar 23 to Apr 6Sow outdoors: Mar 23 to Apr 6
Start indoors: Jan 19 to Feb 2Transplant outside: Mar 9 to Mar 23
Sow outdoors: Jan 19 to Feb 9Plant for fall: Sep 2 to Sep 23
Sow outdoors: Jan 19 to Feb 9Plant for fall: Sep 30 to Oct 21
Sow outdoors: Jan 26 to Mar 9Plant for fall: Oct 14 to Nov 4
Start indoors: Feb 2 to Feb 9Transplant outside: Mar 16 to Mar 23Sow outdoors: Mar 9 to Mar 23Plant for fall: Sep 9 to Sep 23
Start indoors: Feb 2 to Feb 9Sow outdoors: Mar 9 to Mar 23Plant for fall: Sep 16 to Sep 30
Start indoors: Feb 2 to Feb 9Sow outdoors: Mar 9 to Mar 23
Start indoors: Feb 2 to Feb 9Transplant outside: Mar 16 to Mar 30
Sow outdoors: Feb 9 to Mar 9Plant for fall: Sep 2 to Sep 16
Sow outdoors: Feb 9 to Mar 9Plant for fall: Sep 16 to Sep 30
Sow outdoors: Feb 9 to Mar 2
Sow outdoors: Feb 16 to Mar 16Plant for fall: Sep 16 to Sep 30
Sow outdoors: Feb 16 to Mar 9Plant for fall: Sep 30 to Oct 21
Sow outdoors: Mar 9 to Mar 30Plant for fall: Sep 9 to Sep 23
Sow outdoors: Mar 9 to Mar 23
Transplant outside: Mar 16 to Apr 6
Plant for fall: Nov 11 to Dec 16
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in San Gregorio, CA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Dec 8 – Dec 22 | Feb 2 – Feb 16 | — | — |
| Peppers | Dec 22 – Jan 5 | Mar 16 – Mar 30 | — | — |
| Eggplant | Dec 22 – Jan 5 | Mar 16 – Mar 30 | — | — |
| Tomatoes | Jan 5 – Jan 19 | Mar 9 – Mar 23 | — | — |
| Lettuce | Jan 5 – Jan 19 | Feb 9 – Feb 23 | Feb 2 – Mar 9 | Sep 30 – Oct 28 |
| Kale | Jan 5 – Jan 19 | Feb 2 – Feb 16 | Feb 2 – Feb 16 | Sep 16 – Oct 7 |
| Broccoli | Jan 5 – Jan 19 | Feb 16 – Mar 2 | — | Aug 19 – Sep 9 |
| Cabbage | Jan 5 – Jan 19 | Feb 9 – Feb 23 | — | Aug 19 – Sep 9 |
| Cauliflower | Jan 5 – Jan 19 | Feb 16 – Mar 2 | — | Aug 19 – Sep 9 |
| Okra | Jan 19 – Feb 2 | Mar 23 – Apr 6 | Mar 23 – Apr 6 | — |
| Basil | Jan 19 – Feb 2 | Mar 9 – Mar 23 | — | — |
| Peas | — | — | Jan 19 – Feb 9 | Sep 2 – Sep 23 |
| Spinach | — | — | Jan 19 – Feb 9 | Sep 30 – Oct 21 |
| Radishes | — | — | Jan 26 – Mar 9 | Oct 14 – Nov 4 |
| Cucumbers | Feb 2 – Feb 9 | Mar 16 – Mar 23 | Mar 9 – Mar 23 | Sep 9 – Sep 23 |
| Zucchini & Summer Squash | Feb 2 – Feb 9 | — | Mar 9 – Mar 23 | Sep 16 – Sep 30 |
| Winter Squash & Pumpkins | Feb 2 – Feb 9 | — | Mar 9 – Mar 23 | — |
| Melons & Watermelon | Feb 2 – Feb 9 | Mar 16 – Mar 30 | — | — |
| Carrots | — | — | Feb 9 – Mar 9 | Sep 2 – Sep 16 |
| Beets | — | — | Feb 9 – Mar 9 | Sep 16 – Sep 30 |
| Potatoes | — | — | Feb 9 – Mar 2 | — |
| Swiss Chard | — | — | Feb 16 – Mar 16 | Sep 16 – Sep 30 |
| Cilantro | — | — | Feb 16 – Mar 9 | Sep 30 – Oct 21 |
| Green Beans | — | — | Mar 9 – Mar 30 | Sep 9 – Sep 23 |
| Sweet Corn | — | — | Mar 9 – Mar 23 | — |
| Sweet Potatoes | — | Mar 16 – Apr 6 | — | — |
| Garlic | — | — | — | Nov 11 – Dec 16 |
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 San Gregorio 2 Se, CA weather station, 2 km away (elevation 276 ft (84 m)).
Frost dates near San Gregorio
- Loma Mar Mar 2 · Nov 25
- La Honda Mar 21 · Dec 15
- Menlo Park Feb 25 · Nov 25
- Portola Valley Mar 21 · Dec 15
- Pescadero Mar 2 · Nov 25
- Redwood City Jan 17 · Dec 12
- Half Moon Bay Feb 6 · Dec 17
- Atherton Jan 17 · Dec 12
- Stanford Feb 1 · Dec 7
- San Carlos Jan 17 · Dec 12
Frequently asked questions
When is the last frost in San Gregorio, CA?
The median last spring frost in San Gregorio, CA is March 2. There is still about a 10% chance of frost after April 15, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in San Gregorio, CA?
The median first fall frost is November 25, with about a 10% chance of frost before November 1.
How long is the growing season in San Gregorio, CA?
About 268 days between the median last spring frost and first fall frost.
What planting zone is San Gregorio, CA?
San Gregorio, CA is in USDA hardiness zone 9b.