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

Planting zone for 96137 — Westwood, CA

ZIP code 96137 (Westwood, Lassen County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 28 and the first fall frost September 28.

Where ZIP 96137 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostMay 28
First frostSep 28
2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Westwood, 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 Westwood, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 28median — 50% chance of a later frost
Safe for tender plantsJune 13only 10% chance of frost after
First fall frostSeptember 28median — 10% chance by Sep 12
Growing season124 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 18.

From the NOAA station Chester, CA — 11 miles away, elevation 4,531 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 96137

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 16 – Apr 30
SpinachSow outdoors · Apr 16 – May 7
Broccoli, cabbageStart indoors · Mar 19 – Apr 2
Broccoli, cabbageTransplant · May 7 – May 21
Onion setsPlant outdoors · Apr 30 – May 14
PotatoesPlant outdoors · May 7 – May 21
LettuceSow outdoors · Apr 30 – May 14
Carrots, beetsSow outdoors · May 7 – May 21
TomatoesStart indoors · Apr 2 – Apr 16
TomatoesTransplant · Jun 4 – Jun 18
Peppers, eggplantStart indoors · Mar 19 – Apr 2
Peppers, eggplantTransplant · Jun 11 – Jun 25
BeansSow outdoors · Jun 4 – Jun 18
Sweet cornSow outdoors · Jun 4 – Jun 18
Cucumbers, squashSow outdoors · Jun 4 – Jun 18
Fall lettuce, spinachSow outdoors · Aug 3 – Aug 17
GarlicPlant cloves · Sep 14 – Oct 19
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 28) and first fall frost (Sep 28) 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 96137 came on Mar 16 — 42 days earlier than the 1991–2020 average (Apr 27).

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 Westwood, CA

The soil mapped at the center of ZIP 96137 is Inville — very cobbly sandy loam, well drained.

TextureVery cobbly sandy loamdrains and warms fast; dries out and needs more feeding
pH6.6neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Inville family-Sheld family, moderately deep-Rubble Land association, 15 to 50 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 96137; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Westwood, CA

Summer high86 °Faverage high, July
Winter low22 °Faverage low, January
Hot days19days a year at 90 °F or more
Freezing nights188nights a year at 32 °F or less
Growing degree days1,837base 50 °F — the season’s usable heat
Longest day15 h 04 mindaylight on June 21
Shortest day9 h 17 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation34.3 inper year, rain and melted snow
Snowfall110 inper year; 80 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 42 °F, low 22 °F 42°22° JanFebruary: average high 46 °F, low 23 °F 46°23° FebMarch: average high 51 °F, low 26 °F 51°26° MarApril: average high 57 °F, low 30 °F 57°30° AprMay: average high 67 °F, low 37 °F 67°37° MayJune: average high 77 °F, low 43 °F 77°43° JunJuly: average high 86 °F, low 48 °F 86°48° JulAugust: average high 85 °F, low 46 °F 85°46° AugSeptember: average high 79 °F, low 41 °F 79°41° SepOctober: average high 66 °F, low 33 °F 66°33° OctNovember: average high 51 °F, low 26 °F 51°26° NovDecember: average high 41 °F, low 22 °F 41°22° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″January: 6.18 in precipitation, 31.9 in snowfall 6.2❄32 JanFebruary: 5.11 in precipitation, 23.9 in snowfall 5.1❄24 FebMarch: 5.48 in precipitation, 17 in snowfall 5.5❄17 MarApril: 2.51 in precipitation, 3.8 in snowfall 2.5❄4 AprMay: 1.90 in precipitation, 0.2 in snowfall 1.9 MayJune: 0.77 in precipitation 0.8 JunJuly: 0.36 in precipitation 0.4 JulAugust: 0.15 in precipitation 0.1 AugSeptember: 0.31 in precipitation 0.3 SepOctober: 1.70 in precipitation, 0.3 in snowfall 1.7 OctNovember: 3.31 in precipitation, 10.1 in snowfall 3.3❄10 NovDecember: 6.54 in precipitation, 22.4 in snowfall 6.5❄22 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Chester, CA (11 mi away); precipitation: Chester, CA (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

960207a
Chester, CA · 11 mi
960617a
Mill Creek, CA · 16 mi
960717a
Old Station, CA · 20 mi
959237b
Canyon Dam, CA · 20 mi
960637b
Mineral, CA · 21 mi
960407a
Hat Creek, CA · 26 mi
959477b
Greenville, CA · 30 mi
961277a
Susanville, CA · 31 mi

California planting zones →

Questions about 96137

What planting zone is ZIP code 96137?

ZIP code 96137 (Westwood, CA) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Westwood, CA?

The median last spring frost (32 °F) near 96137 is May 28; after June 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Chester station.

When is the first frost in Westwood, CA?

The median first fall frost near 96137 is September 28, giving a median frost-free growing season of 124 days.

When should I plant tomatoes in 96137?

Start tomato seeds indoors around Apr 2 – Apr 16 and set transplants outside around Jun 4 – Jun 18, one to three weeks after the median last frost.

How much rain and snow does 96137 get?

About 34.3 inches of precipitation a year and 110 inches of snowfall (NOAA 1991–2020 normals, Chester station).

How hot do summers get in Westwood, CA?

The average high peaks at 86 °F in July, with about 19 days a year at 90 °F or more.

What kind of soil does 96137 have?

The USDA soil survey maps Inville at the center of ZIP 96137: very cobbly sandy loam, well drained, pH about 6.6 (neutral).

Did spring come early in Westwood, CA in 2026?

Spring leaf-out near 96137 came on Mar 16 in 2026, 42 days earlier than the 1991–2020 average (Apr 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Westwood, CA?

Long-day onions: the longest day near 96137 is 15 h 04 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).