Half Moon Bay, CA planting zone & frost dates
Half Moon Bay is in USDA hardiness zone 10a. The last spring frost usually comes around February 6 and the first fall frost around December 17, for a growing season of about 328 days.
Planting calendar for Half Moon Bay
Dates are counted from the average last spring frost (February 6) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Dec 12 – Dec 26 Transplant outdoors: Feb 13 – Feb 20 |
| Peppers | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Feb 20 – Feb 27 |
| Eggplant | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Feb 20 – Feb 27 |
| Broccoli | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Jan 9 – Jan 23 |
| Cabbage | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Jan 9 – Jan 23 |
| Onions (sets) | Plant outdoors: Jan 9 – Jan 23 |
| Peas | Sow outdoors: Dec 26 – Jan 9 |
| Spinach | Sow outdoors: Dec 26 – Jan 9 |
| Lettuce | Sow outdoors: Jan 9 – Jan 23 |
| Carrots | Sow outdoors: Jan 9 – Jan 23 |
| Potatoes | Plant outdoors: Jan 9 – Jan 23 |
| Beans | Sow outdoors: Feb 13 – Feb 20 |
| Sweet corn | Sow outdoors: Feb 13 – Feb 20 |
| Cucumbers | Sow outdoors: Feb 13 – Feb 20 |
| Squash & zucchini | Sow outdoors: Feb 13 – Feb 20 |
| Basil | Start seeds indoors: Dec 26 – Jan 9 Transplant outdoors: Feb 13 – Feb 20 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 22 (8 weeks before the average first fall frost on Dec 17).
Useful for zone 10a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Dec 17 | Feb 6 | Mar 25 |
| First 32°F frost in fall is before | Feb 13 | Dec 17 | Nov 25 |
How to read it: in spring there is a 10% chance of a frost after March 25, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 25. A hard freeze (28°F) usually ends around January 5.
Hardiness zone by ZIP code in Half Moon Bay
- 94019 zone 10a
Nearby cities
- Hillsborough zone 10a
- Burlingame zone 10a
- Millbrae zone 10a
- San Mateo zone 10a
- Pacifica zone 10a
- Belmont zone 10a, last frost Jan 17
- San Bruno zone 10a
- San Carlos zone 10a, last frost Jan 17
Questions
What growing zone is Half Moon Bay, CA?
Half Moon Bay is in USDA Plant Hardiness Zone 10a (average extreme winter low 30°F to 35°F), according to the USDA 2023 map.
When is the last frost in Half Moon Bay?
The average last spring frost (32°F) in Half Moon Bay is February 6. There is still a 10% chance of frost until March 25.
When can I plant tomatoes in Half Moon Bay?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Feb 13 – Feb 20. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Half Moon Bay, CA (USC00043714), 1.6 km (1.0 mi) from the city center, elevation 8 m, based on 25 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.