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

Planting zone for 95138 — San Jose, CA

ZIP code 95138 (San Jose, Santa Clara County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is May 3 and the first fall frost November 18.

Where ZIP 95138 is

Outlined: the ZIP code area · 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 frostMay 3
First frostNov 18
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 San Jose, 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 San Jose, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 3median — 50% chance of a later frost
Safe for tender plantsJune 5only 10% chance of frost after
First fall frostNovember 18median — 10% chance by Oct 22
Growing season197 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around December 7.

From the NOAA station Mt Hamilton, CA — 9 miles away, elevation 4,206 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 95138

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 22 – Apr 5
SpinachSow outdoors · Mar 22 – Apr 12
Broccoli, cabbageStart indoors · Feb 22 – Mar 8
Broccoli, cabbageTransplant · Apr 12 – Apr 26
Onion setsPlant outdoors · Apr 5 – Apr 19
PotatoesPlant outdoors · Apr 12 – Apr 26
LettuceSow outdoors · Apr 5 – Apr 19
Carrots, beetsSow outdoors · Apr 12 – Apr 26
TomatoesStart indoors · Mar 8 – Mar 22
TomatoesTransplant · May 10 – May 24
Peppers, eggplantStart indoors · Feb 22 – Mar 8
Peppers, eggplantTransplant · May 17 – May 31
BeansSow outdoors · May 10 – May 24
Sweet cornSow outdoors · May 10 – May 24
Cucumbers, squashSow outdoors · May 10 – May 24
Fall lettuce, spinachSow outdoors · Sep 23 – Oct 7
GarlicPlant cloves · Nov 4 – Dec 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 3) and first fall frost (Nov 18) 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 95138 came on Jan 28 — 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 San Jose, CA

The soil mapped at the center of ZIP 95138 is Montara — sandy loam, somewhat excessively drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH7.1neutral; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Montara-Santerhill complex, 15 to 30 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 95138; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in San Jose, CA

Summer high79 °Faverage high, July
Winter low38 °Faverage low, February
Hot days3days a year at 90 °F or more
Freezing nights45nights a year at 32 °F or less
Growing degree days3,173base 50 °F — the season’s usable heat
Longest day14 h 44 mindaylight on June 21
Shortest day9 h 36 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation18.8 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 50 °F, low 39 °F 50°39° JanFebruary: average high 49 °F, low 38 °F 49°38° FebMarch: average high 51 °F, low 39 °F 51°39° MarApril: average high 55 °F, low 41 °F 55°41° AprMay: average high 62 °F, low 47 °F 62°47° MayJune: average high 71 °F, low 56 °F 71°56° JunJuly: average high 79 °F, low 65 °F 79°65° JulAugust: average high 79 °F, low 65 °F 79°65° AugSeptember: average high 75 °F, low 60 °F 75°60° SepOctober: average high 66 °F, low 52 °F 66°52° OctNovember: average high 55 °F, low 43 °F 55°43° NovDecember: average high 49 °F, low 38 °F 49°38° Dec

Precipitation by month inches

0″1″2″3″4″January: 3.83 in precipitation 3.8 JanFebruary: 3.46 in precipitation 3.5 FebMarch: 2.67 in precipitation 2.7 MarApril: 1.46 in precipitation 1.5 AprMay: 0.71 in precipitation 0.7 MayJune: 0.19 in precipitation 0.2 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.10 in precipitation 0.1 SepOctober: 0.85 in precipitation 0.8 OctNovember: 1.89 in precipitation 1.9 NovDecember: 3.60 in precipitation 3.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Mt Hamilton, CA (9 mi away); precipitation: San Jose 3.5 Ene, CA (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9b.

951399b
San Jose, CA · 2 mi
950139b
Coyote, CA · 2 mi
951199b
San Jose, CA · 3 mi
951939b
San Jose, CA · 4 mi
951239b
San Jose, CA · 5 mi
951119b
San Jose, CA · 5 mi
951219b
San Jose, CA · 5 mi
951539b
San Jose, CA · 5 mi

All 55 ZIP codes in San Jose → · California planting zones →

Questions about 95138

What planting zone is ZIP code 95138?

ZIP code 95138 (San Jose, 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 San Jose, CA?

The median last spring frost (32 °F) near 95138 is May 3; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mt Hamilton station.

When is the first frost in San Jose, CA?

The median first fall frost near 95138 is November 18, giving a median frost-free growing season of 197 days.

When should I plant tomatoes in 95138?

Start tomato seeds indoors around Mar 8 – Mar 22 and set transplants outside around May 10 – May 24, one to three weeks after the median last frost.

How much rain and snow does 95138 get?

About 18.8 inches of precipitation a year (NOAA 1991–2020 normals, San Jose 3.5 Ene station).

How hot do summers get in San Jose, CA?

The average high peaks at 79 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 95138 have?

The USDA soil survey maps Montara at the center of ZIP 95138: sandy loam, somewhat excessively drained, pH about 7.1 (neutral).

Did spring come early in San Jose, CA in 2026?

Spring leaf-out near 95138 came on Jan 28 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 San Jose, CA?

Intermediate onions: the longest day near 95138 is 14 h 44 min, so day-neutral types bulb best; long-day varieties may not bulb fully.