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

Planting zone for Alameda, CA

Alameda, CA is in USDA zone 10a across its 2 ZIP codes.

Alameda on the zone map

Outlined: its 2 ZIP code areas · 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.

Zone10a30 to 35 °F
ZIP codes2
Last frostrare
First frostrare
Growing seasonall year

10a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Alameda, 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 Oakland Metro Intl Airport, CA, elevation 7 ft) the median growing season is 356 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 94501 came on Jan 24 — about the same time as 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 Alameda, CA

The soil mapped at the center of ZIP 94501 is Baywood — loamy sand, somewhat excessively drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding
pH6.2slightly acidic; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Baywood complex.

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 94501; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Alameda, CA

Summer high75 °Faverage high, September
Winter low45 °Faverage low, January
Hot days5days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days3,570base 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
Precipitation22.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 60 °F, low 45 °F 60°45° JanFebruary: average high 62 °F, low 47 °F 62°47° FebMarch: average high 65 °F, low 49 °F 65°49° MarApril: average high 67 °F, low 50 °F 67°50° AprMay: average high 69 °F, low 53 °F 69°53° MayJune: average high 72 °F, low 55 °F 72°55° JunJuly: average high 72 °F, low 57 °F 72°57° JulAugust: average high 73 °F, low 58 °F 73°58° AugSeptember: average high 75 °F, low 57 °F 75°57° SepOctober: average high 73 °F, low 55 °F 73°55° OctNovember: average high 66 °F, low 49 °F 66°49° NovDecember: average high 60 °F, low 45 °F 60°45° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.35 in precipitation 4.3 JanFebruary: 4.35 in precipitation 4.3 FebMarch: 3.21 in precipitation 3.2 MarApril: 1.37 in precipitation 1.4 AprMay: 0.75 in precipitation 0.8 MayJune: 0.20 in precipitation 0.2 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.05 in precipitation 0.1 AugSeptember: 0.10 in precipitation 0.1 SepOctober: 1.13 in precipitation 1.1 OctNovember: 2.44 in precipitation 2.4 NovDecember: 4.66 in precipitation 4.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Oakland Museum, CA (2 mi away); precipitation: Oakland Museum, CA (2 mi away). Daylight is calculated from latitude.

ZIP codes in Alameda

California planting zones →

Questions about Alameda

What planting zone is Alameda, CA?

Alameda, CA is in USDA hardiness zone 10a on the 2023 map (10a: 30 to 35 °F).

What kind of onions grow in Alameda, CA?

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

How much rain and snow does Alameda, CA get?

About 22.6 inches of precipitation a year (NOAA 1991–2020 normals).