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

Planting zone for 92254 — Mecca, CA

ZIP code 92254 (Mecca, Riverside County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 92254 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.

Zone10a30 to 35 °F
Coldest night−1.1 to 1.7 °C
Last frostrare
First frostrare
2012 zone9b

Was 9b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 10a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mecca, 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 Mecca Fire Stn, CA — 5 miles away, elevation -184 ft) the median growing season is 352 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 92254 came on Jan 17 — 6 days earlier than the 1991–2020 average (Jan 23).

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 Mecca, CA

The soil mapped at the center of ZIP 92254 is Carsitas — gravelly sand, somewhat excessively drained.

TextureGravelly sanddrains and warms fast; dries out and needs more feeding
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter0.3%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Carsitas gravelly sand, 0 to 9 percent slopes.

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 92254; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mecca, CA

Summer high107 °Faverage high, July
Winter low42 °Faverage low, December
Hot days196days a year at 90 °F or more
Freezing nights8nights a year at 32 °F or less
Growing degree days9,062base 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 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 70 °F, low 44 °F 70°44° JanFebruary: average high 74 °F, low 47 °F 74°47° FebMarch: average high 81 °F, low 54 °F 81°54° MarApril: average high 87 °F, low 59 °F 87°59° AprMay: average high 95 °F, low 66 °F 95°66° MayJune: average high 103 °F, low 72 °F 103°72° JunJuly: average high 107 °F, low 80 °F 107°80° JulAugust: average high 106 °F, low 80 °F 106°80° AugSeptember: average high 102 °F, low 74 °F 102°74° SepOctober: average high 91 °F, low 62 °F 91°62° OctNovember: average high 78 °F, low 50 °F 78°50° NovDecember: average high 69 °F, low 42 °F 69°42° Dec

Precipitation by month inches

0″1″January: 0.60 in precipitation 0.6 JanFebruary: 0.56 in precipitation 0.6 FebMarch: 0.32 in precipitation 0.3 MarApril: 0.17 in precipitation 0.2 AprMay: 0.01 in precipitation 0.0 MayJune: 0.00 in precipitation 0.0 JunJuly: 0.21 in precipitation 0.2 JulAugust: 0.08 in precipitation 0.1 AugSeptember: 0.30 in precipitation 0.3 SepOctober: 0.23 in precipitation 0.2 OctNovember: 0.20 in precipitation 0.2 NovDecember: 0.37 in precipitation 0.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Mecca Fire Stn, CA (5 mi away); precipitation: Mecca Fire Stn, CA (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 10a.

California planting zones →

Questions about 92254

What planting zone is ZIP code 92254?

ZIP code 92254 (Mecca, CA) is in USDA hardiness zone 10a on the 2023 map: the coldest night of an average winter reaches 30 to 35 °F (−1.1 to 1.7 °C).

How much rain and snow does 92254 get?

About 3 inches of precipitation a year (NOAA 1991–2020 normals, Mecca Fire Stn station).

How hot do summers get in Mecca, CA?

The average high peaks at 107 °F in July, with about 196 days a year at 90 °F or more.

What kind of soil does 92254 have?

The USDA soil survey maps Carsitas at the center of ZIP 92254: gravelly sand, somewhat excessively drained, pH about 8.2 (alkaline).

Did spring come early in Mecca, CA in 2026?

Spring leaf-out near 92254 came on Jan 17 in 2026, 6 days earlier than the 1991–2020 average (Jan 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mecca, CA?

Intermediate onions: the longest day near 92254 is 14 h 23 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 92254 change?

Yes. The 2012 USDA map put 92254 in zone 9b; the 2023 map puts it in zone 10a. The newer map uses 1991–2020 data and more weather stations.