San Francisco International Airport, CA Frost Dates & Growing Season

The two dates every San Francisco International Airport garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Dec 29
~50% chance of frost after
First fall frost
Dec 26
~50% chance of frost before
Growing season
362 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 11 Dec 29 Jan 13
First fall frost Jan 13 Dec 26 Dec 11

Computed from NOAA 1991–2020 climate normals at the SAN FRANCISCO INTL AP 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 San Francisco International Airport

Computed from San Francisco International Airport'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 Nov 3 – Nov 17 Jan 5 – Jan 12
🫑 Peppers Oct 20 – Nov 3 Jan 12 – Jan 19
🥬 Lettuce Nov 17 – Dec 1 Dec 1 – Dec 15 Dec 1 – Dec 29
🫛 Peas Nov 17 – Dec 1
🥕 Carrots Dec 8 – Dec 29
🥦 Broccoli Nov 10 – Nov 24 Dec 8 – Dec 22
🥬 Kale Nov 17 – Dec 1 Dec 1 – Dec 15 Dec 1 – Dec 15
🥒 Cucumbers Dec 1 – Dec 8 Jan 5 – Jan 12 Jan 5 – Jan 12
🥒 Zucchini Dec 1 – Dec 8 Jan 5 – Jan 12 Jan 5 – Jan 12
🫘 Green Beans (Bush) Jan 5 – Jan 12
🌽 Sweet Corn Jan 5 – Jan 12
🌿 Basil Nov 17 – Dec 1 Jan 5 – Jan 12 Jan 12 – Jan 19
🧄 Garlic Fall: Nov 14 – Dec 12

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 San Francisco International Airport's dates automatically after a lookup.

Reading the season in San Francisco International Airport

With roughly 362 frost-free days, San Francisco International Airport 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 26 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in San Francisco International Airport, CA?

The average last spring frost in San Francisco International Airport is around Dec 29, 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 San Francisco International Airport, CA?

The average first fall frost in San Francisco International Airport arrives around Dec 26. 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 San Francisco International Airport?

About 362 frost-free days on average, from Dec 29 to Dec 26. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is San Francisco International Airport 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.