Half Moon Bay, CA Frost Dates & Growing Season

The two dates every Half Moon Bay garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Feb 6
~50% chance of frost after
First fall frost
Dec 17
~50% chance of frost before
Growing season
314 days
frost-free stretch
USDA zone
≈ 10b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Dec 17 Feb 6 Mar 25
First fall frost Feb 13 Dec 17 Nov 25
Hard freeze (28°F), median last Jan 5 · first Dec 31

Computed from NOAA 1991–2020 climate normals at the HALF MOON BAY station. "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for Half Moon Bay

Computed from Half Moon Bay's own frost dates. Click any crop for the full zone-10 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Dec 12 – Dec 26 Feb 13 – Feb 20
🫑 Peppers Nov 28 – Dec 12 Feb 20 – Feb 27
🥬 Lettuce Dec 26 – Jan 9 Jan 9 – Jan 23 Jan 9 – Feb 6
🫛 Peas Dec 26 – Jan 9
🥕 Carrots Jan 16 – Feb 6
🥦 Broccoli Dec 19 – Jan 2 Jan 16 – Jan 30
🥬 Kale Dec 26 – Jan 9 Jan 9 – Jan 23 Jan 9 – Jan 23
🥒 Cucumbers Jan 9 – Jan 16 Feb 13 – Feb 20 Feb 13 – Feb 20
🥒 Zucchini Jan 9 – Jan 16 Feb 13 – Feb 20 Feb 13 – Feb 20
🫘 Green Beans (Bush) Feb 13 – Feb 20
🌽 Sweet Corn Feb 13 – Feb 20
🌿 Basil Dec 26 – Jan 9 Feb 13 – Feb 20 Feb 20 – Feb 27
🧄 Garlic Fall: Nov 5 – Dec 3

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use Half Moon Bay's dates automatically after a lookup.

Reading the season in Half Moon Bay

With roughly 314 frost-free days, Half Moon Bay gardens fit long-season crops — melons, winter squash, sweet potatoes — with room left for spring and fall rounds of greens and roots. The first frost around Dec 17 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Half Moon Bay, CA?

The average last spring frost in Half Moon Bay is around Feb 6, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in Half Moon Bay, CA?

The average first fall frost in Half Moon Bay arrives around Dec 17. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in Half Moon Bay?

About 314 frost-free days on average, from Feb 6 to Dec 17. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Half Moon Bay in?

USDA zone 10b on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.