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

Planting zone for 94804 — Richmond, CA

ZIP code 94804 (Richmond, Contra Costa County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 94804 is

Outlined: the ZIP code area · 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
Coldest night−1.1 to 1.7 °C
Last frostrare
First frostrare
2012 zone10a

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 10a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Richmond, 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 Richmond, CA — 2 miles away, elevation 20 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 94804 came on Jan 23 — 4 days earlier than the 1991–2020 average (Jan 27).

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 Richmond, CA

The soil mapped at the center of ZIP 94804 is Clear Lake — clay, poorly drained.

TextureClayholds water and nutrients; slow to drain and warm up
pH7.0neutral; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Clear Lake clay, 0 to 15 percent slopes, MLRA 15.

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 94804; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Richmond, CA

Summer high75 °Faverage high, September
Winter low44 °Faverage low, January
Hot days5days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days3,322base 50 °F — the season’s usable heat
Longest day14 h 48 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
Precipitation22.8 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 58 °F, low 44 °F 58°44° JanFebruary: average high 61 °F, low 46 °F 61°46° FebMarch: average high 64 °F, low 47 °F 64°47° MarApril: average high 67 °F, low 49 °F 67°49° AprMay: average high 69 °F, low 52 °F 69°52° MayJune: average high 72 °F, low 54 °F 72°54° JunJuly: average high 71 °F, low 55 °F 71°55° JulAugust: average high 72 °F, low 56 °F 72°56° AugSeptember: average high 75 °F, low 56 °F 75°56° SepOctober: average high 73 °F, low 54 °F 73°54° OctNovember: average high 65 °F, low 49 °F 65°49° NovDecember: average high 58 °F, low 44 °F 58°44° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.55 in precipitation 4.5 JanFebruary: 4.66 in precipitation 4.7 FebMarch: 2.98 in precipitation 3.0 MarApril: 1.48 in precipitation 1.5 AprMay: 0.78 in precipitation 0.8 MayJune: 0.24 in precipitation 0.2 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.05 in precipitation 0.1 AugSeptember: 0.11 in precipitation 0.1 SepOctober: 1.02 in precipitation 1.0 OctNovember: 2.46 in precipitation 2.5 NovDecember: 4.48 in precipitation 4.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Richmond, CA (2 mi away); precipitation: El Cerrito 0.3 Wnw, CA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 10a.

9480210a
Richmond, CA · 2 mi
9480710a
Richmond, CA · 2 mi
9480810a
Richmond, CA · 2 mi
9485010a
Richmond, CA · 2 mi
9480510a
Richmond, CA · 2 mi
9453010a
El Cerrito, CA · 2 mi
9470610a
Albany, CA · 3 mi
9470710a
Berkeley, CA · 3 mi

All 7 ZIP codes in Richmond → · California planting zones →

Questions about 94804

What planting zone is ZIP code 94804?

ZIP code 94804 (Richmond, CA) is in USDA hardiness zone 10a on the 2023 map: the coldest night of an average winter reaches 30 to 35 °F (−1.1 to 1.7 °C).

How much rain and snow does 94804 get?

About 22.8 inches of precipitation a year (NOAA 1991–2020 normals, El Cerrito 0.3 Wnw station).

How hot do summers get in Richmond, 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 94804 have?

The USDA soil survey maps Clear Lake at the center of ZIP 94804: clay, poorly drained, pH about 7.0 (neutral).

Did spring come early in Richmond, CA in 2026?

Spring leaf-out near 94804 came on Jan 23 in 2026, 4 days earlier than the 1991–2020 average (Jan 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Richmond, CA?

Intermediate onions: the longest day near 94804 is 14 h 48 min, so day-neutral types bulb best; long-day varieties may not bulb fully.