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

Planting zone for Fremont, CA

Fremont, CA is in USDA zones 9b to 10a across its 5 ZIP codes.

Fremont on the zone map

Outlined: its 4 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.

Zones9b–10a25 to 35 °F
ZIP codes5
Last frostrare
First frostrare
Growing seasonall year

9b 3 ZIPs   10a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Fremont, 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 Fremont, CA, elevation 39 ft) the median growing season is 353 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 94536 came on Jan 26 — about the same time as the 1991–2020 average (Jan 28).

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 Fremont, CA

The center of ZIP 94536 is mapped as Water: 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 94536; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fremont, CA

Summer high78 °Faverage high, July
Winter low43 °Faverage low, January
Hot days13days a year at 90 °F or more
Freezing nights3nights a year at 32 °F or less
Growing degree days3,622base 50 °F — the season’s usable heat
Longest day14 h 46 mindaylight on June 21
Shortest day9 h 34 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation15.9 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 59 °F, low 43 °F 59°43° JanFebruary: average high 61 °F, low 44 °F 61°44° FebMarch: average high 65 °F, low 46 °F 65°46° MarApril: average high 68 °F, low 48 °F 68°48° AprMay: average high 71 °F, low 52 °F 71°52° MayJune: average high 75 °F, low 55 °F 75°55° JunJuly: average high 78 °F, low 57 °F 78°57° JulAugust: average high 78 °F, low 57 °F 78°57° AugSeptember: average high 78 °F, low 56 °F 78°56° SepOctober: average high 73 °F, low 52 °F 73°52° OctNovember: average high 65 °F, low 46 °F 65°46° NovDecember: average high 58 °F, low 43 °F 58°43° Dec

Precipitation by month inches

0″1″2″3″4″January: 3.00 in precipitation 3.0 JanFebruary: 3.17 in precipitation 3.2 FebMarch: 2.52 in precipitation 2.5 MarApril: 1.22 in precipitation 1.2 AprMay: 0.50 in precipitation 0.5 MayJune: 0.16 in precipitation 0.2 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.02 in precipitation 0.0 AugSeptember: 0.10 in precipitation 0.1 SepOctober: 0.69 in precipitation 0.7 OctNovember: 1.59 in precipitation 1.6 NovDecember: 2.97 in precipitation 3.0 Dec

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

ZIP codes in Fremont

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Questions about Fremont

What planting zone is Fremont, CA?

Fremont, CA is in USDA hardiness zones 9b to 10a on the 2023 map (9b: 25 to 30 °F; 10a: 30 to 35 °F).

What kind of onions grow in Fremont, CA?

Intermediate onions: the longest day is 14 h 46 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Fremont, CA get?

About 15.9 inches of precipitation a year (NOAA 1991–2020 normals).