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

Planting zone for Trona, CA

Trona, CA is in USDA zone 9a across its 2 ZIP codes. The median last spring frost is February 15 and the first fall frost November 28.

Trona 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.

Zone9a20 to 25 °F
ZIP codes2
Last frostFeb 15
First frostNov 28
Growing season285 days

9a 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 Trona, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 15median — 50% chance of a later frost
Safe for tender plantsMarch 4only 10% chance of frost after
First fall frostNovember 28median — 10% chance by Nov 11
Growing season285 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 23 and returns around December 10.

From the NOAA station Trona, CA, elevation 1,696 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 Trona

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 4 – Jan 18
SpinachSow outdoors · Jan 4 – Jan 25
Broccoli, cabbageStart indoors · Dec 7 – Dec 21
Broccoli, cabbageTransplant · Jan 25 – Feb 8
Onion setsPlant outdoors · Jan 18 – Feb 1
PotatoesPlant outdoors · Jan 25 – Feb 8
LettuceSow outdoors · Jan 18 – Feb 1
Carrots, beetsSow outdoors · Jan 25 – Feb 8
TomatoesStart indoors · Dec 21 – Jan 4
TomatoesTransplant · Feb 22 – Mar 8
Peppers, eggplantStart indoors · Dec 7 – Dec 21
Peppers, eggplantTransplant · Mar 1 – Mar 15
BeansSow outdoors · Feb 22 – Mar 8
Sweet cornSow outdoors · Feb 22 – Mar 8
Cucumbers, squashSow outdoors · Feb 22 – Mar 8
Fall lettuce, spinachSow outdoors · Oct 3 – Oct 17
GarlicPlant cloves · Nov 14 – Dec 19
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 15) and first fall frost (Nov 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 93592 came on Jan 28 — 3 days earlier than the 1991–2020 average (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 Trona, CA

The soil mapped at the center of ZIP 93592 is Torriorthents — extremely gravelly sand, somewhat excessively drained.

TextureExtremely gravelly sanddrains and warms fast; dries out and needs more feeding
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter0.2%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Torriorthents, Torripsamments, and Haplargids; hyperthermic fan piedmonts.

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 93592; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Trona, CA

Summer high107 °Faverage high, July
Winter low34 °Faverage low, December
Hot days137days a year at 90 °F or more
Freezing nights26nights a year at 32 °F or less
Growing degree days7,073base 50 °F — the season’s usable heat
Longest day14 h 35 mindaylight on June 21
Shortest day9 h 44 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation3.6 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°110°120°32 °FJanuary: average high 60 °F, low 35 °F 60°35° JanFebruary: average high 66 °F, low 39 °F 66°39° FebMarch: average high 73 °F, low 45 °F 73°45° MarApril: average high 81 °F, low 51 °F 81°51° AprMay: average high 90 °F, low 59 °F 90°59° MayJune: average high 100 °F, low 68 °F 100°68° JunJuly: average high 107 °F, low 74 °F 107°74° JulAugust: average high 106 °F, low 74 °F 106°74° AugSeptember: average high 99 °F, low 67 °F 99°67° SepOctober: average high 86 °F, low 55 °F 86°55° OctNovember: average high 71 °F, low 42 °F 71°42° NovDecember: average high 60 °F, low 34 °F 60°34° Dec

Precipitation by month inches

0″1″January: 0.77 in precipitation 0.8 JanFebruary: 0.91 in precipitation 0.9 FebMarch: 0.48 in precipitation 0.5 MarApril: 0.11 in precipitation 0.1 AprMay: 0.07 in precipitation 0.1 MayJune: 0.02 in precipitation 0.0 JunJuly: 0.09 in precipitation 0.1 JulAugust: 0.06 in precipitation 0.1 AugSeptember: 0.09 in precipitation 0.1 SepOctober: 0.20 in precipitation 0.2 OctNovember: 0.24 in precipitation 0.2 NovDecember: 0.58 in precipitation 0.6 Dec

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

ZIP codes in Trona

935629a
20 to 25 °F
935929a
20 to 25 °F

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Questions about Trona

What planting zone is Trona, CA?

Trona, CA is in USDA hardiness zone 9a on the 2023 map (9a: 20 to 25 °F).

When is the last frost in Trona, CA?

The median last spring frost is February 15 and the median first fall frost is November 28 (NOAA 1991–2020 normals, Trona station).

When can I plant a garden in Trona, CA?

Cool-season crops like peas and spinach go in around Jan 4 – Jan 25; tomatoes, peppers, beans and squash after about Feb 22, once frost risk has passed.

What kind of onions grow in Trona, CA?

Intermediate onions: the longest day is 14 h 35 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Trona, CA get?

About 3.6 inches of precipitation a year (NOAA 1991–2020 normals).