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

Planting zone for 95021 — Gilroy, CA

ZIP code 95021 (Gilroy, Santa Clara County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 24 and the first fall frost November 27.

Where ZIP 95021 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.

Zone9b25 to 30 °F
Coldest night−3.9 to −1.1 °C
Last frostFeb 24
First frostNov 27
2012 zone9b

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 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Gilroy, 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 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 — within 1 mile, 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 95021

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 95021 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 95021 is Pleasanton — loam, well drained.

TextureLoama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.8%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Pleasanton loam, 0 to 2 percent slopes, MLRA 14.

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 95021; 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.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9b.

950209b
Gilroy, CA · <1 mi
950469b
San Martin, CA · 6 mi
950049b
Aromas, CA · 10 mi
950379b
Morgan Hill, CA · 10 mi
950769b
Watsonville, CA · 11 mi
950389b
Morgan Hill, CA · 11 mi
950779b
Watsonville, CA · 12 mi
950199b
Freedom, CA · 13 mi

All 2 ZIP codes in Gilroy → · California planting zones →

Questions about 95021

What planting zone is ZIP code 95021?

ZIP code 95021 (Gilroy, CA) is in USDA hardiness zone 9b on the 2023 map: the coldest night of an average winter reaches 25 to 30 °F (−3.9 to −1.1 °C).

When is the last frost in Gilroy, CA?

The median last spring frost (32 °F) near 95021 is February 24; after April 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Gilroy station.

When is the first frost in Gilroy, CA?

The median first fall frost near 95021 is November 27, giving a median frost-free growing season of 277 days.

When should I plant tomatoes in 95021?

Start tomato seeds indoors around Dec 30 – Jan 13 and set transplants outside around Mar 3 – Mar 17, one to three weeks after the median last frost.

How much rain and snow does 95021 get?

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

How hot do summers get in Gilroy, CA?

The average high peaks at 87 °F in July, with about 48 days a year at 90 °F or more.

What kind of soil does 95021 have?

The USDA soil survey maps Pleasanton at the center of ZIP 95021: loam, well drained, pH about 6.5 (neutral).

Did spring come early in Gilroy, CA in 2026?

Spring leaf-out near 95021 came on Jan 27 in 2026, about the same as the 1991–2020 average (Jan 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Gilroy, CA?

Intermediate onions: the longest day near 95021 is 14 h 42 min, so day-neutral types bulb best; long-day varieties may not bulb fully.