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

Planting zone for 92233 — Calipatria, CA

ZIP code 92233 (Calipatria, Imperial County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F.

Where ZIP 92233 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 frostrare
First frostrare
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 Calipatria, 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

A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station Brawley 2 Sw, CA — 14 miles away, elevation -98 ft) the median growing season is 335 days. When frost does come, it is a midwinter night or two; cover tender plants when a freeze is forecast.

Frost data: NOAA NCEI U.S. Climate Normals 1991–2020.

When spring arrived in 2026

In 2026, spring leaf-out near 92233 came on Jan 28 — 6 days later than 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 Calipatria, CA

The soil mapped at the center of ZIP 92233 is Imperial — silty clay, moderately well drained.

TextureSilty clayholds water and nutrients; slow to drain and warm up
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter0.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if irrigated and reclaimed of excess salts and sodiumUSDA classification

Map unit: Imperial silty clay, wet.

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 92233; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Calipatria, CA

Summer high108 °Faverage high, July
Winter low41 °Faverage low, January
Hot days181days a year at 90 °F or more
Freezing nights6nights a year at 32 °F or less
Growing degree days8,739base 50 °F — the season’s usable heat
Longest day14 h 21 mindaylight on June 21
Shortest day9 h 57 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation2.5 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 72 °F, low 41 °F 72°41° JanFebruary: average high 75 °F, low 45 °F 75°45° FebMarch: average high 81 °F, low 50 °F 81°50° MarApril: average high 87 °F, low 54 °F 87°54° AprMay: average high 95 °F, low 61 °F 95°61° MayJune: average high 104 °F, low 68 °F 104°68° JunJuly: average high 108 °F, low 77 °F 108°77° JulAugust: average high 108 °F, low 78 °F 108°78° AugSeptember: average high 104 °F, low 71 °F 104°71° SepOctober: average high 93 °F, low 60 °F 93°60° OctNovember: average high 80 °F, low 49 °F 80°49° NovDecember: average high 70 °F, low 41 °F 70°41° Dec

Precipitation by month inches

0″1″January: 0.50 in precipitation 0.5 JanFebruary: 0.49 in precipitation 0.5 FebMarch: 0.36 in precipitation 0.4 MarApril: 0.12 in precipitation 0.1 AprMay: 0.03 in precipitation 0.0 MayJune: 0.02 in precipitation 0.0 JunJuly: 0.10 in precipitation 0.1 JulAugust: 0.13 in precipitation 0.1 AugSeptember: 0.22 in precipitation 0.2 SepOctober: 0.08 in precipitation 0.1 OctNovember: 0.14 in precipitation 0.1 NovDecember: 0.36 in precipitation 0.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Brawley 2 Sw, CA (14 mi away); precipitation: Niland, CA (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

922819b
Westmorland, CA · 9 mi
922579b
Niland, CA · 13 mi
9222710a
Brawley, CA · 14 mi
9227510a
Salton City, CA · 22 mi
9225110a
Imperial, CA · 23 mi
9227310a
Seeley, CA · 26 mi
9224310a
El Centro, CA · 27 mi
9224410a
El Centro, CA · 27 mi

California planting zones →

Questions about 92233

What planting zone is ZIP code 92233?

ZIP code 92233 (Calipatria, 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).

How much rain and snow does 92233 get?

About 2.5 inches of precipitation a year (NOAA 1991–2020 normals, Niland station).

How hot do summers get in Calipatria, CA?

The average high peaks at 108 °F in July, with about 181 days a year at 90 °F or more.

What kind of soil does 92233 have?

The USDA soil survey maps Imperial at the center of ZIP 92233: silty clay, moderately well drained, pH about 8.2 (alkaline).

Did spring come early in Calipatria, CA in 2026?

Spring leaf-out near 92233 came on Jan 28 in 2026, 6 days later than the 1991–2020 average (Jan 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Calipatria, CA?

Intermediate onions: the longest day near 92233 is 14 h 21 min, so day-neutral types bulb best; long-day varieties may not bulb fully.