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

Planting zone for 92591 — Temecula, CA

ZIP code 92591 (Temecula, Riverside County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F.

Where ZIP 92591 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 Temecula, 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 Fallbrook 5 Ne, CA — 8 miles away, elevation 1,142 ft) the median growing season is 365 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 92591 came on Jan 19 — 5 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 Temecula, CA

The soil mapped at the center of ZIP 92591 is Hanford — coarse sandy loam, well drained.

TextureCoarse sandy loamdrains and warms fast; dries out and needs more feeding
pH6.7neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Hanford coarse sandy loam, 2 to 8 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 92591; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Temecula, CA

Summer high89 °Faverage high, August
Winter low46 °Faverage low, February
Hot days60days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days5,564base 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
Precipitation13.2 inper year, rain and melted snow

Average high and low, by month

40°50°60°70°80°90°100°January: average high 68 °F, low 47 °F 68°47° JanFebruary: average high 67 °F, low 46 °F 67°46° FebMarch: average high 70 °F, low 48 °F 70°48° MarApril: average high 72 °F, low 51 °F 72°51° AprMay: average high 75 °F, low 53 °F 75°53° MayJune: average high 81 °F, low 56 °F 81°56° JunJuly: average high 87 °F, low 60 °F 87°60° JulAugust: average high 89 °F, low 62 °F 89°62° AugSeptember: average high 88 °F, low 62 °F 88°62° SepOctober: average high 83 °F, low 58 °F 83°58° OctNovember: average high 74 °F, low 52 °F 74°52° NovDecember: average high 67 °F, low 46 °F 67°46° Dec

Precipitation by month inches

0″1″2″3″4″January: 2.93 in precipitation 2.9 JanFebruary: 3.08 in precipitation 3.1 FebMarch: 1.63 in precipitation 1.6 MarApril: 1.04 in precipitation 1.0 AprMay: 0.30 in precipitation 0.3 MayJune: 0.10 in precipitation 0.1 JunJuly: 0.14 in precipitation 0.1 JulAugust: 0.22 in precipitation 0.2 AugSeptember: 0.28 in precipitation 0.3 SepOctober: 0.66 in precipitation 0.7 OctNovember: 0.75 in precipitation 0.8 NovDecember: 2.07 in precipitation 2.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Fallbrook 5 Ne, CA (8 mi away); precipitation: Murrieta 4.3 Ene, CA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

All 5 ZIP codes in Temecula → · California planting zones →

Questions about 92591

What planting zone is ZIP code 92591?

ZIP code 92591 (Temecula, 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 92591 get?

About 13.2 inches of precipitation a year (NOAA 1991–2020 normals, Murrieta 4.3 Ene station).

How hot do summers get in Temecula, CA?

The average high peaks at 89 °F in August, with about 60 days a year at 90 °F or more.

What kind of soil does 92591 have?

The USDA soil survey maps Hanford at the center of ZIP 92591: coarse sandy loam, well drained, pH about 6.7 (neutral).

Did spring come early in Temecula, CA in 2026?

Spring leaf-out near 92591 came on Jan 19 in 2026, 5 days earlier than the 1991–2020 average (Jan 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Temecula, CA?

Intermediate onions: the longest day near 92591 is 14 h 23 min, so day-neutral types bulb best; long-day varieties may not bulb fully.