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

Planting zone for Campbell, CA

Campbell, CA is in USDA zone 9b across its 3 ZIP codes. The median last spring frost is February 2 and the first fall frost December 6.

Campbell on the zone map

Outlined: its 1 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.

Zone9b25 to 30 °F
ZIP codes3
Last frostFeb 2
First frostDec 6
Growing season310 days

9b 3 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 in Campbell, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 2median — 50% chance of a later frost
Safe for tender plantsMarch 14only 10% chance of frost after
First fall frostDecember 6median — 10% chance by Nov 16
Growing season310 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 1 and returns around December 19.

From the NOAA station Los Gatos, CA, elevation 364 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in Campbell

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 22 – Jan 5
SpinachSow outdoors · Dec 22 – Jan 12
Broccoli, cabbageStart indoors · Nov 24 – Dec 8
Broccoli, cabbageTransplant · Jan 12 – Jan 26
Onion setsPlant outdoors · Jan 5 – Jan 19
PotatoesPlant outdoors · Jan 12 – Jan 26
LettuceSow outdoors · Jan 5 – Jan 19
Carrots, beetsSow outdoors · Jan 12 – Jan 26
TomatoesStart indoors · Dec 8 – Dec 22
TomatoesTransplant · Feb 9 – Feb 23
Peppers, eggplantStart indoors · Nov 24 – Dec 8
Peppers, eggplantTransplant · Feb 16 – Mar 2
BeansSow outdoors · Feb 9 – Feb 23
Sweet cornSow outdoors · Feb 9 – Feb 23
Cucumbers, squashSow outdoors · Feb 9 – Feb 23
Fall lettuce, spinachSow outdoors · Oct 11 – Oct 25
GarlicPlant cloves · Nov 22 – Dec 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 2) and first fall frost (Dec 6) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 95009 came on Jan 27 — 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 Campbell, CA

The soil mapped at the center of ZIP 95009 is Stevenscreek — sandy loam, well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH5.4strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Stevenscreek complex, 0 to 2 percent slopes.

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 95009; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Campbell, CA

Summer high85 °Faverage high, July
Winter low40 °Faverage low, January
Hot days27days a year at 90 °F or more
Freezing nights13nights a year at 32 °F or less
Growing degree days3,769base 50 °F — the season’s usable heat
Longest day14 h 44 mindaylight on June 21
Shortest day9 h 35 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation17.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 59 °F, low 40 °F 59°40° JanFebruary: average high 62 °F, low 41 °F 62°41° FebMarch: average high 66 °F, low 43 °F 66°43° MarApril: average high 70 °F, low 45 °F 70°45° AprMay: average high 76 °F, low 49 °F 76°49° MayJune: average high 82 °F, low 53 °F 82°53° JunJuly: average high 85 °F, low 56 °F 85°56° JulAugust: average high 85 °F, low 56 °F 85°56° AugSeptember: average high 83 °F, low 54 °F 83°54° SepOctober: average high 76 °F, low 49 °F 76°49° OctNovember: average high 65 °F, low 43 °F 65°43° NovDecember: average high 58 °F, low 40 °F 58°40° Dec

Precipitation by month inches

0″1″2″3″4″January: 3.56 in precipitation 3.6 JanFebruary: 3.68 in precipitation 3.7 FebMarch: 2.60 in precipitation 2.6 MarApril: 1.17 in precipitation 1.2 AprMay: 0.57 in precipitation 0.6 MayJune: 0.16 in precipitation 0.2 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.09 in precipitation 0.1 SepOctober: 0.76 in precipitation 0.8 OctNovember: 1.80 in precipitation 1.8 NovDecember: 3.22 in precipitation 3.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Los Gatos, CA (4 mi away); precipitation: San Jose 6.2 W, CA (2 mi away). Daylight is calculated from latitude.

ZIP codes in Campbell

950089b
25 to 30 °F
950099b
25 to 30 °F
950119b
25 to 30 °F

California planting zones →

Questions about Campbell

What planting zone is Campbell, CA?

Campbell, CA is in USDA hardiness zone 9b on the 2023 map (9b: 25 to 30 °F).

When is the last frost in Campbell, CA?

The median last spring frost is February 2 and the median first fall frost is December 6 (NOAA 1991–2020 normals, Los Gatos station).

When can I plant a garden in Campbell, CA?

Cool-season crops like peas and spinach go in around Dec 22 – Jan 12; tomatoes, peppers, beans and squash after about Feb 9, once frost risk has passed.

What kind of onions grow in Campbell, CA?

Intermediate onions: the longest day is 14 h 44 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Campbell, CA get?

About 17.6 inches of precipitation a year (NOAA 1991–2020 normals).