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

Planting zone for 94623 — Oakland, CA

ZIP code 94623 (Oakland, Alameda County) is in USDA zone 10b: the coldest winter night averages 35 to 40 °F.

Where ZIP 94623 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 Oakland, 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 Berkeley, CA — 5 miles away, elevation 312 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 94623 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 Oakland, CA

The soil mapped at the center of ZIP 94623 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 94623; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Oakland, 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 32 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 (within 1 mile); precipitation: Oakland Museum, CA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

9460410a
Oakland, CA · <1 mi
9462410a
Oakland, CA · <1 mi
9464910a
Oakland, CA · <1 mi
9465910a
Oakland, CA · <1 mi
9466010a
Oakland, CA · <1 mi
946619b
Oakland, CA · <1 mi
9466610a
Oakland, CA · <1 mi
9461710b
Oakland, CA · <1 mi

All 26 ZIP codes in Oakland → · California planting zones →

Questions about 94623

What planting zone is ZIP code 94623?

ZIP code 94623 (Oakland, 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 94623 get?

About 22.6 inches of precipitation a year (NOAA 1991–2020 normals, Oakland Museum station).

How hot do summers get in Oakland, CA?

The average high peaks at 75 °F in September, with about 5 days a year at 90 °F or more.

What kind of soil does 94623 have?

The USDA soil survey maps Baywood at the center of ZIP 94623: loamy sand, somewhat excessively drained, pH about 6.2 (slightly acidic).

Did spring come early in Oakland, CA in 2026?

Spring leaf-out near 94623 came on Jan 24 in 2026, about the same as the 1991–2020 average (Jan 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Oakland, CA?

Intermediate onions: the longest day near 94623 is 14 h 47 min, so day-neutral types bulb best; long-day varieties may not bulb fully.