Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Stockton, CA

Stockton, CA is in USDA zone 9b across its 19 ZIP codes. The median last spring frost is February 5 and the first fall frost December 8.

Stockton on the zone map

Outlined: its 11 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 codes19

Last frostFeb 5

First frostDec 8

Growing season305 days

9b 19 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 Stockton, CA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostFebruary 5median — 50% chance of a later frost

Safe for tender plantsMarch 11only 10% chance of frost after

First fall frostDecember 8median — 10% chance by Nov 17

Growing season305 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 11 and returns around December 23.

From the NOAA station Stockton Fire Stn 4, CA, elevation 13 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 Stockton

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Dec 25 – Jan 8

SpinachSow outdoors · Dec 25 – Jan 15

Broccoli, cabbageStart indoors · Nov 27 – Dec 11

Broccoli, cabbageTransplant · Jan 15 – Jan 29

Onion setsPlant outdoors · Jan 8 – Jan 22

PotatoesPlant outdoors · Jan 15 – Jan 29

LettuceSow outdoors · Jan 8 – Jan 22

Carrots, beetsSow outdoors · Jan 15 – Jan 29

TomatoesStart indoors · Dec 11 – Dec 25

TomatoesTransplant · Feb 12 – Feb 26

Peppers, eggplantStart indoors · Nov 27 – Dec 11

Peppers, eggplantTransplant · Feb 19 – Mar 5

BeansSow outdoors · Feb 12 – Feb 26

Sweet cornSow outdoors · Feb 12 – Feb 26

Cucumbers, squashSow outdoors · Feb 12 – Feb 26

Fall lettuce, spinachSow outdoors · Oct 13 – Oct 27

GarlicPlant cloves · Nov 24 – Dec 29

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 5) and first fall frost (Dec 8) 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 95204 came on Jan 31 — about the same time as the 1991–2020 average (Jan 31).

average
Jan 312026
Jan 31

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 Stockton, CA

The soil mapped at the center of ZIP 95204 is Jacktone — clay, somewhat poorly drained.

TextureClayholds water and nutrients; slow to drain and warm up

pH7.5slightly alkaline; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter3.5%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Jacktone-Urban land 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 95204; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Stockton, CA

Summer high95 °Faverage high, July

Winter low39 °Faverage low, January

Hot days90days a year at 90 °F or more

Freezing nights25nights a year at 32 °F or less

Growing degree days5,277base 50 °F — the season’s usable heat

Longest day14 h 48 mindaylight on June 21

Shortest day9 h 31 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation17.3 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Stockton Fire Stn 4, CA (2 mi away); precipitation: Stockton Fire Stn 4, CA (2 mi away). Daylight is calculated from latitude.

Questions about Stockton

What planting zone is Stockton, CA?

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

When is the last frost in Stockton, CA?

The median last spring frost is February 5 and the median first fall frost is December 8 (NOAA 1991–2020 normals, Stockton Fire Stn 4 station).

When can I plant a garden in Stockton, CA?

Cool-season crops like peas and spinach go in around Dec 25 – Jan 15; tomatoes, peppers, beans and squash after about Feb 12, once frost risk has passed.

What kind of onions grow in Stockton, CA?

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

How much rain and snow does Stockton, CA get?

About 17.3 inches of precipitation a year (NOAA 1991–2020 normals).