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

Planting zone for Gilroy, CA

Gilroy, CA is in USDA zone 9b across its 2 ZIP codes. The median last spring frost is February 24 and the first fall frost November 27.

Gilroy 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 codes2
Last frostFeb 24
First frostNov 27
Growing season277 days

9b 2 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 Gilroy, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 24median — 50% chance of a later frost
Safe for tender plantsApril 4only 10% chance of frost after
First fall frostNovember 27median — 10% chance by Nov 10
Growing season277 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 16 and returns around December 12.

From the NOAA station Gilroy, CA, elevation 194 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 Gilroy

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 13 – Jan 27
SpinachSow outdoors · Jan 13 – Feb 3
Broccoli, cabbageStart indoors · Dec 16 – Dec 30
Broccoli, cabbageTransplant · Feb 3 – Feb 17
Onion setsPlant outdoors · Jan 27 – Feb 10
PotatoesPlant outdoors · Feb 3 – Feb 17
LettuceSow outdoors · Jan 27 – Feb 10
Carrots, beetsSow outdoors · Feb 3 – Feb 17
TomatoesStart indoors · Dec 30 – Jan 13
TomatoesTransplant · Mar 3 – Mar 17
Peppers, eggplantStart indoors · Dec 16 – Dec 30
Peppers, eggplantTransplant · Mar 10 – Mar 24
BeansSow outdoors · Mar 3 – Mar 17
Sweet cornSow outdoors · Mar 3 – Mar 17
Cucumbers, squashSow outdoors · Mar 3 – Mar 17
Fall lettuce, spinachSow outdoors · Oct 2 – Oct 16
GarlicPlant cloves · Nov 13 – Dec 18
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 24) and first fall frost (Nov 27) 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 95020 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 Gilroy, CA

The soil mapped at the center of ZIP 95020 is Zamora — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Zamora clay loam, 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 95020; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Gilroy, CA

Summer high87 °Faverage high, July
Winter low37 °Faverage low, December
Hot days48days a year at 90 °F or more
Freezing nights16nights a year at 32 °F or less
Growing degree days3,961base 50 °F — the season’s usable heat
Longest day14 h 42 mindaylight on June 21
Shortest day9 h 37 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation19.8 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 61 °F, low 38 °F 61°38° JanFebruary: average high 64 °F, low 40 °F 64°40° FebMarch: average high 68 °F, low 43 °F 68°43° MarApril: average high 72 °F, low 45 °F 72°45° AprMay: average high 77 °F, low 49 °F 77°49° MayJune: average high 83 °F, low 52 °F 83°52° JunJuly: average high 87 °F, low 54 °F 87°54° JulAugust: average high 87 °F, low 54 °F 87°54° AugSeptember: average high 85 °F, low 53 °F 85°53° SepOctober: average high 79 °F, low 48 °F 79°48° OctNovember: average high 68 °F, low 42 °F 68°42° NovDecember: average high 60 °F, low 37 °F 60°37° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.55 in precipitation 4.5 JanFebruary: 4.27 in precipitation 4.3 FebMarch: 2.59 in precipitation 2.6 MarApril: 1.30 in precipitation 1.3 AprMay: 0.56 in precipitation 0.6 MayJune: 0.15 in precipitation 0.1 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.03 in precipitation 0.0 AugSeptember: 0.04 in precipitation 0.0 SepOctober: 0.85 in precipitation 0.8 OctNovember: 1.74 in precipitation 1.7 NovDecember: 3.69 in precipitation 3.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Gilroy, CA (within 1 mile); precipitation: Gilroy, CA (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Gilroy

950209b
25 to 30 °F
950219b
25 to 30 °F

California planting zones →

Questions about Gilroy

What planting zone is Gilroy, CA?

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

When is the last frost in Gilroy, CA?

The median last spring frost is February 24 and the median first fall frost is November 27 (NOAA 1991–2020 normals, Gilroy station).

When can I plant a garden in Gilroy, CA?

Cool-season crops like peas and spinach go in around Jan 13 – Feb 3; tomatoes, peppers, beans and squash after about Mar 3, once frost risk has passed.

What kind of onions grow in Gilroy, CA?

Intermediate onions: the longest day is 14 h 42 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Gilroy, CA get?

About 19.8 inches of precipitation a year (NOAA 1991–2020 normals).