When to plant in Half Moon Bay, CA
USDA Zone 10aHalf Moon Bay, California frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
With about 314 frost-free days, Half Moon Bay supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Zone 10a is warm enough that Half Moon Bay can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
The average last spring frost in Half Moon Bay is now 6 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
HALF MOON BAY · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Half Moon Bay’s own odds, recorded at HALF MOON BAY.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 1 | Apr 3 | Feb 23 | Oct 20 | Nov 20 | Dec 16 |
| 32°F | Mar 25 | Feb 6 | Dec 17 | Nov 25 | Dec 17 | Feb 13 |
| 28°F | Feb 26 | Jan 5 | Dec 5 | Dec 4 | Dec 31 | Feb 23 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Half Moon Bay, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 17 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Half Moon Bay planting FAQ
When is the last spring frost in Half Moon Bay, CA?
Plan for the last spring frost in Half Moon Bay around February 6 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Half Moon Bay, CA?
Expect Half Moon Bay's first fall frost near December 17 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Half Moon Bay in?
Half Moon Bay is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Half Moon Bay?
There are roughly 314 frost-free days in Half Moon Bay (a long growing season), running from the average last frost around February 6 to the first fall frost near December 17.
When should I plant tomatoes in Half Moon Bay?
In Half Moon Bay, start tomato seeds indoors around December 12–December 26, then transplant seedlings outdoors around February 13 once the danger of frost has passed.
Never miss a window in Half Moon Bay
An email when it’s time to start seeds, transplant, and sow — timed to Half Moon Bay’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Hillsborough · 12 km
- Belmont · 14 km
- Millbrae · 15 km
- Burlingame · 15 km
- San Mateo · 15 km
- San Carlos · 16 km
- Pacifica · 16 km
- San Bruno · 18 km
Frost dates recorded at HALF MOON BAY, 1 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Half Moon Bay, CA — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00043714. Retrieved from https://blissgarden.com/california/half-moon-bay.