Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 94140 — San Francisco, CA

ZIP code 94140 (San Francisco, City and County of San Francisco) is in USDA zone 10b: the coldest winter night averages 35 to 40 °F.

Where ZIP 94140 is

tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone10b35 to 40 °F
Coldest night1.7 to 4.4 °C
Last frostrare
First frostrare
2012 zone10b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 10b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for San Francisco, CA…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates

A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station San Francisco Oceanside, CA — 6 miles away, elevation 7 ft) the median growing season is 365 days. When frost does come, it is a midwinter night or two; cover tender plants when a freeze is forecast.

Frost data: NOAA NCEI U.S. Climate Normals 1991–2020.

When spring arrived in 2026

In 2026, spring leaf-out near 94140 came on Jan 23 — 3 days earlier than the 1991–2020 average (Jan 26).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Soil in San Francisco, CA

The center of ZIP 94140 is mapped as Urban land: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 94140; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in San Francisco, CA

Summer high70 °Faverage high, September
Winter low47 °Faverage low, January
Hot days3days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days2,872base 50 °F — the season’s usable heat
Longest day14 h 47 mindaylight on June 21
Shortest day9 h 33 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation22.9 inper year, rain and melted snow

Average high and low, by month

40°50°60°70°80°January: average high 58 °F, low 47 °F 58°47° JanFebruary: average high 60 °F, low 48 °F 60°48° FebMarch: average high 62 °F, low 49 °F 62°49° MarApril: average high 63 °F, low 50 °F 63°50° AprMay: average high 64 °F, low 51 °F 64°51° MayJune: average high 67 °F, low 53 °F 67°53° JunJuly: average high 66 °F, low 54 °F 66°54° JulAugust: average high 68 °F, low 56 °F 68°56° AugSeptember: average high 70 °F, low 56 °F 70°56° SepOctober: average high 70 °F, low 54 °F 70°54° OctNovember: average high 64 °F, low 51 °F 64°51° NovDecember: average high 58 °F, low 47 °F 58°47° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.40 in precipitation 4.4 JanFebruary: 4.37 in precipitation 4.4 FebMarch: 3.15 in precipitation 3.1 MarApril: 1.60 in precipitation 1.6 AprMay: 0.70 in precipitation 0.7 MayJune: 0.20 in precipitation 0.2 JunJuly: 0.01 in precipitation 0.0 JulAugust: 0.06 in precipitation 0.1 AugSeptember: 0.10 in precipitation 0.1 SepOctober: 0.94 in precipitation 0.9 OctNovember: 2.60 in precipitation 2.6 NovDecember: 4.76 in precipitation 4.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: San Francisco Dwtn, CA (within 1 mile); precipitation: San Francisco Dwtn, CA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

All 50 ZIP codes in San Francisco → · California planting zones →

Questions about 94140

What planting zone is ZIP code 94140?

ZIP code 94140 (San Francisco, CA) is in USDA hardiness zone 10b on the 2023 map: the coldest night of an average winter reaches 35 to 40 °F (1.7 to 4.4 °C).

How much rain and snow does 94140 get?

About 22.9 inches of precipitation a year (NOAA 1991–2020 normals, San Francisco Dwtn station).

How hot do summers get in San Francisco, CA?

The average high peaks at 70 °F in September, with about 3 days a year at 90 °F or more.

Did spring come early in San Francisco, CA in 2026?

Spring leaf-out near 94140 came on Jan 23 in 2026, 3 days earlier than the 1991–2020 average (Jan 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in San Francisco, CA?

Intermediate onions: the longest day near 94140 is 14 h 47 min, so day-neutral types bulb best; long-day varieties may not bulb fully.