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

Planting zone for 92226 — Blythe, CA

ZIP code 92226 (Blythe, Riverside County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is January 25 and the first fall frost December 12.

Where ZIP 92226 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 frostJan 25
First frostDec 12
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 Blythe, 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 Blythe, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJanuary 25median — 50% chance of a later frost
Safe for tender plantsFebruary 24only 10% chance of frost after
First fall frostDecember 12median — 10% chance by Nov 28
Growing season325 daysfrost-free, median

A hard freeze (28 °F) usually ends around December 30 and returns around December 22.

From the NOAA station Blythe, CA — 3 miles away, elevation 269 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 92226

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 14 – Dec 28
SpinachSow outdoors · Dec 14 – Jan 4
Broccoli, cabbageStart indoors · Nov 16 – Nov 30
Broccoli, cabbageTransplant · Jan 4 – Jan 18
Onion setsPlant outdoors · Dec 28 – Jan 11
PotatoesPlant outdoors · Jan 4 – Jan 18
LettuceSow outdoors · Dec 28 – Jan 11
Carrots, beetsSow outdoors · Jan 4 – Jan 18
TomatoesStart indoors · Nov 30 – Dec 14
TomatoesTransplant · Feb 1 – Feb 15
Peppers, eggplantStart indoors · Nov 16 – Nov 30
Peppers, eggplantTransplant · Feb 8 – Feb 22
BeansSow outdoors · Feb 1 – Feb 15
Sweet cornSow outdoors · Feb 1 – Feb 15
Cucumbers, squashSow outdoors · Feb 1 – Feb 15
Fall lettuce, spinachSow outdoors · Oct 17 – Oct 31
GarlicPlant cloves · Nov 28 – Jan 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jan 25) and first fall frost (Dec 12) 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 92226 came on Jan 22 — about the same time as the 1991–2020 average (Jan 22).

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 Blythe, CA

The soil mapped at the center of ZIP 92226 is Holtville — silty clay, well drained.

TextureSilty clayholds water and nutrients; slow to drain and warm up
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.25%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigated and reclaimed of excess salts and sodiumUSDA classification

Map unit: Holtville silty clay.

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 92226; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Blythe, CA

Summer high110 °Faverage high, July
Winter low38 °Faverage low, December
Hot days188days a year at 90 °F or more
Freezing nights9nights a year at 32 °F or less
Growing degree days8,641base 50 °F — the season’s usable heat
Longest day14 h 23 mindaylight on June 21
Shortest day9 h 55 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

30°40°50°60°70°80°90°100°110°120°32 °FJanuary: average high 69 °F, low 40 °F 69°40° JanFebruary: average high 73 °F, low 43 °F 73°43° FebMarch: average high 81 °F, low 49 °F 81°49° MarApril: average high 89 °F, low 55 °F 89°55° AprMay: average high 98 °F, low 63 °F 98°63° MayJune: average high 106 °F, low 71 °F 106°71° JunJuly: average high 110 °F, low 78 °F 110°78° JulAugust: average high 109 °F, low 78 °F 109°78° AugSeptember: average high 104 °F, low 71 °F 104°71° SepOctober: average high 91 °F, low 57 °F 91°57° OctNovember: average high 78 °F, low 47 °F 78°47° NovDecember: average high 66 °F, low 38 °F 66°38° Dec

Precipitation by month inches

0″1″January: 0.57 in precipitation 0.6 JanFebruary: 0.64 in precipitation 0.6 FebMarch: 0.42 in precipitation 0.4 MarApril: 0.12 in precipitation 0.1 AprMay: 0.07 in precipitation 0.1 MayJune: 0.00 in precipitation 0.0 JunJuly: 0.18 in precipitation 0.2 JulAugust: 0.35 in precipitation 0.3 AugSeptember: 0.38 in precipitation 0.4 SepOctober: 0.22 in precipitation 0.2 OctNovember: 0.16 in precipitation 0.2 NovDecember: 0.50 in precipitation 0.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Blythe, CA (3 mi away); precipitation: Blythe, CA (3 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.

922259b
Blythe, CA · 8 mi
853349b
Ehrenberg, AZ · 17 mi
853289b
Cibola, AZ · 24 mi
853599b
Quartzsite, AZ · 24 mi
853469a
Quartzsite, AZ · 28 mi
853719a
Poston, AZ · 30 mi
853449b
Parker, AZ · 31 mi
9226610a
Palo Verde, CA · 31 mi

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

Questions about 92226

What planting zone is ZIP code 92226?

ZIP code 92226 (Blythe, 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 Blythe, CA?

The median last spring frost (32 °F) near 92226 is January 25; after February 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Blythe station.

When is the first frost in Blythe, CA?

The median first fall frost near 92226 is December 12, giving a median frost-free growing season of 325 days.

When should I plant tomatoes in 92226?

Start tomato seeds indoors around Nov 30 – Dec 14 and set transplants outside around Feb 1 – Feb 15, one to three weeks after the median last frost.

How much rain and snow does 92226 get?

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

How hot do summers get in Blythe, CA?

The average high peaks at 110 °F in July, with about 188 days a year at 90 °F or more.

What kind of soil does 92226 have?

The USDA soil survey maps Holtville at the center of ZIP 92226: silty clay, well drained, pH about 8.2 (alkaline).

Did spring come early in Blythe, CA in 2026?

Spring leaf-out near 92226 came on Jan 22 in 2026, about the same as the 1991–2020 average (Jan 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Blythe, CA?

Intermediate onions: the longest day near 92226 is 14 h 23 min, so day-neutral types bulb best; long-day varieties may not bulb fully.