Planting zone for 92281 — Westmorland, CA
ZIP code 92281 (Westmorland, Imperial County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F.
Where ZIP 92281 is
Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoomNot 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.
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 ServiceLoading the forecast for Westmorland, 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 — 7 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 92281 came on Jan 22 — about the same time as the 1991–2020 average (Jan 22).
Jan 222026
Jan 22
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 Westmorland, CA
The soil mapped at the center of ZIP 92281 is Imperial — silty clay loam, somewhat poorly drained.
Map unit: Imperial-Glenbar silty clay loams complex, 0 to 2 percent slopes, 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 92281; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Westmorland, CA
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Brawley 2 Sw, CA (7 mi away); precipitation: Brawley 2 Sw, CA (7 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.
Questions about 92281
What planting zone is ZIP code 92281?
ZIP code 92281 (Westmorland, 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 92281 get?
About 2.4 inches of precipitation a year (NOAA 1991–2020 normals, Brawley 2 Sw station).
How hot do summers get in Westmorland, 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 92281 have?
The USDA soil survey maps Imperial at the center of ZIP 92281: silty clay loam, somewhat poorly drained, pH about 8.4 (alkaline).
Did spring come early in Westmorland, CA in 2026?
Spring leaf-out near 92281 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 Westmorland, CA?
Intermediate onions: the longest day near 92281 is 14 h 20 min, so day-neutral types bulb best; long-day varieties may not bulb fully.