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

Planting zone for 92282 — Whitewater, CA

ZIP code 92282 (Whitewater, Riverside County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 25 and the first fall frost December 15.

Where ZIP 92282 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 frostFeb 25
First frostDec 15
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 Whitewater, 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 Whitewater, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 25median — 50% chance of a later frost
Safe for tender plantsApril 3only 10% chance of frost after
First fall frostDecember 15median — 10% chance by Nov 23
Growing season297 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 25 and returns around January 6.

From the NOAA station Morongo Valley N, CA — 10 miles away, elevation 3,146 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 92282

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 14 – Jan 28
SpinachSow outdoors · Jan 14 – Feb 4
Broccoli, cabbageStart indoors · Dec 17 – Dec 31
Broccoli, cabbageTransplant · Feb 4 – Feb 18
Onion setsPlant outdoors · Jan 28 – Feb 11
PotatoesPlant outdoors · Feb 4 – Feb 18
LettuceSow outdoors · Jan 28 – Feb 11
Carrots, beetsSow outdoors · Feb 4 – Feb 18
TomatoesStart indoors · Dec 31 – Jan 14
TomatoesTransplant · Mar 4 – Mar 18
Peppers, eggplantStart indoors · Dec 17 – Dec 31
Peppers, eggplantTransplant · Mar 11 – Mar 25
BeansSow outdoors · Mar 4 – Mar 18
Sweet cornSow outdoors · Mar 4 – Mar 18
Cucumbers, squashSow outdoors · Mar 4 – Mar 18
Fall lettuce, spinachSow outdoors · Oct 20 – Nov 3
GarlicPlant cloves · Dec 1 – Jan 5
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 25) and first fall frost (Dec 15) 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 92282 came on Jan 18 — 6 days earlier than the 1991–2020 average (Jan 24).

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 Whitewater, CA

The soil mapped at the center of ZIP 92282 is Lithic Torriorthents — very gravelly fine sandy loam, somewhat excessively drained.

TextureVery gravelly fine sandy loamdrains and warms fast; dries out and needs more feeding
pH7.8slightly alkaline; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter0.3%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Lithic Torriorthents, Typic Haplocalcids, and Rock outcrop; hyperthermic hills and mountains.

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 92282; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Whitewater, CA

Summer high94 °Faverage high, July
Winter low40 °Faverage low, December
Hot days91days a year at 90 °F or more
Freezing nights13nights a year at 32 °F or less
Growing degree days5,671base 50 °F — the season’s usable heat
Longest day14 h 25 mindaylight on June 21
Shortest day9 h 53 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation9.4 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 59 °F, low 41 °F 59°41° JanFebruary: average high 61 °F, low 42 °F 61°42° FebMarch: average high 66 °F, low 45 °F 66°45° MarApril: average high 73 °F, low 48 °F 73°48° AprMay: average high 80 °F, low 54 °F 80°54° MayJune: average high 89 °F, low 63 °F 89°63° JunJuly: average high 94 °F, low 69 °F 94°69° JulAugust: average high 94 °F, low 70 °F 94°70° AugSeptember: average high 88 °F, low 66 °F 88°66° SepOctober: average high 78 °F, low 57 °F 78°57° OctNovember: average high 67 °F, low 47 °F 67°47° NovDecember: average high 59 °F, low 40 °F 59°40° Dec

Precipitation by month inches

0″1″2″3″January: 2.72 in precipitation 2.7 JanFebruary: 2.90 in precipitation 2.9 FebMarch: 0.90 in precipitation 0.9 MarApril: 0.22 in precipitation 0.2 AprMay: 0.07 in precipitation 0.1 MayJune: 0.02 in precipitation 0.0 JunJuly: 0.19 in precipitation 0.2 JulAugust: 0.22 in precipitation 0.2 AugSeptember: 0.17 in precipitation 0.2 SepOctober: 0.17 in precipitation 0.2 OctNovember: 0.31 in precipitation 0.3 NovDecember: 1.48 in precipitation 1.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Morongo Valley N, CA (10 mi away); precipitation: Morongo Valley N, CA (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

9225810a
North Palm Springs, CA · 6 mi
922309b
Cabazon, CA · 7 mi
922569b
Morongo Valley, CA · 8 mi
9224010a
Desert Hot Springs, CA · 8 mi
9226210a
Palm Springs, CA · 9 mi
922209b
Banning, CA · 10 mi
925498a
Idyllwild, CA · 11 mi
923397b
Forest Falls, CA · 13 mi

California planting zones →

Questions about 92282

What planting zone is ZIP code 92282?

ZIP code 92282 (Whitewater, 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 Whitewater, CA?

The median last spring frost (32 °F) near 92282 is February 25; after April 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Morongo Valley N station.

When is the first frost in Whitewater, CA?

The median first fall frost near 92282 is December 15, giving a median frost-free growing season of 297 days.

When should I plant tomatoes in 92282?

Start tomato seeds indoors around Dec 31 – Jan 14 and set transplants outside around Mar 4 – Mar 18, one to three weeks after the median last frost.

How much rain and snow does 92282 get?

About 9.4 inches of precipitation a year (NOAA 1991–2020 normals, Morongo Valley N station).

How hot do summers get in Whitewater, CA?

The average high peaks at 94 °F in July, with about 91 days a year at 90 °F or more.

What kind of soil does 92282 have?

The USDA soil survey maps Lithic Torriorthents at the center of ZIP 92282: very gravelly fine sandy loam, somewhat excessively drained, pH about 7.8 (slightly alkaline).

Did spring come early in Whitewater, CA in 2026?

Spring leaf-out near 92282 came on Jan 18 in 2026, 6 days earlier than the 1991–2020 average (Jan 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Whitewater, CA?

Intermediate onions: the longest day near 92282 is 14 h 25 min, so day-neutral types bulb best; long-day varieties may not bulb fully.