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

Planting zone for 94850 — Richmond, CA

ZIP code 94850 (Richmond, Contra Costa County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 94850 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.

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 94850 came on Jan 26 — about the same time as 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 94850 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 94850; 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
Precipitation24.2 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: 4.90 in precipitation 4.9 JanFebruary: 4.66 in precipitation 4.7 FebMarch: 3.40 in precipitation 3.4 MarApril: 1.66 in precipitation 1.7 AprMay: 0.83 in precipitation 0.8 MayJune: 0.23 in precipitation 0.2 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.11 in precipitation 0.1 SepOctober: 1.11 in precipitation 1.1 OctNovember: 2.50 in precipitation 2.5 NovDecember: 4.80 in precipitation 4.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Richmond, CA (2 mi away); precipitation: El Cerrito 1.3 Nw, CA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 10a.

9480210a
Richmond, CA · <1 mi
9480710a
Richmond, CA · <1 mi
9480810a
Richmond, CA · <1 mi
9480510a
Richmond, CA · 1 mi
9480410a
Richmond, CA · 2 mi
9453010a
El Cerrito, CA · 3 mi
9480110a
Richmond, CA · 3 mi
9480610a
San Pablo, CA · 3 mi

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

Questions about 94850

What planting zone is ZIP code 94850?

ZIP code 94850 (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 94850 get?

About 24.2 inches of precipitation a year (NOAA 1991–2020 normals, El Cerrito 1.3 Nw 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 94850 have?

The USDA soil survey maps Clear Lake at the center of ZIP 94850: clay, poorly drained, pH about 7.0 (neutral).

Did spring come early in Richmond, CA in 2026?

Spring leaf-out near 94850 came on Jan 26 in 2026, about the same as 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 94850 is 14 h 48 min, so day-neutral types bulb best; long-day varieties may not bulb fully.