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

Planting zone for 91750 — La Verne, CA

ZIP code 91750 (La Verne, Los Angeles County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 91750 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 La Verne, 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 Pomona/Fairplex, CA — 4 miles away, elevation 1,001 ft) the median growing season is 354 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 91750 came on Jan 17 — 7 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 La Verne, CA

The soil mapped at the center of ZIP 91750 is Lithic Haploxerolls — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH5.0strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter75%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Lithic Haploxerolls-Lithic Argixerolls complex, 20 to 55 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 91750; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in La Verne, CA

Summer high92 °Faverage high, August
Winter low42 °Faverage low, December
Hot days71days a year at 90 °F or more
Freezing nights3nights a year at 32 °F or less
Growing degree days5,557base 50 °F — the season’s usable heat
Longest day14 h 26 mindaylight on June 21
Shortest day9 h 52 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation14.5 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 68 °F, low 43 °F 68°43° JanFebruary: average high 67 °F, low 45 °F 67°45° FebMarch: average high 72 °F, low 47 °F 72°47° MarApril: average high 76 °F, low 50 °F 76°50° AprMay: average high 78 °F, low 54 °F 78°54° MayJune: average high 84 °F, low 57 °F 84°57° JunJuly: average high 90 °F, low 62 °F 90°62° JulAugust: average high 92 °F, low 63 °F 92°63° AugSeptember: average high 89 °F, low 60 °F 89°60° SepOctober: average high 81 °F, low 54 °F 81°54° OctNovember: average high 74 °F, low 47 °F 74°47° NovDecember: average high 67 °F, low 42 °F 67°42° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.91 in precipitation 2.9 JanFebruary: 4.15 in precipitation 4.2 FebMarch: 2.12 in precipitation 2.1 MarApril: 0.97 in precipitation 1.0 AprMay: 0.22 in precipitation 0.2 MayJune: 0.06 in precipitation 0.1 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.03 in precipitation 0.0 AugSeptember: 0.01 in precipitation 0.0 SepOctober: 0.97 in precipitation 1.0 OctNovember: 0.74 in precipitation 0.7 NovDecember: 2.29 in precipitation 2.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Pomona/Fairplex, CA (4 mi away); precipitation: Pomona/Fairplex, CA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 10a.

California planting zones →

Questions about 91750

What planting zone is ZIP code 91750?

ZIP code 91750 (La Verne, 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 91750 get?

About 14.5 inches of precipitation a year (NOAA 1991–2020 normals, Pomona/Fairplex station).

How hot do summers get in La Verne, CA?

The average high peaks at 92 °F in August, with about 71 days a year at 90 °F or more.

What kind of soil does 91750 have?

The USDA soil survey maps Lithic Haploxerolls at the center of ZIP 91750: slightly decomposed plant material, well drained, pH about 5.0 (strongly acidic).

Did spring come early in La Verne, CA in 2026?

Spring leaf-out near 91750 came on Jan 17 in 2026, 7 days earlier than the 1991–2020 average (Jan 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in La Verne, CA?

Intermediate onions: the longest day near 91750 is 14 h 26 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 91750 change?

Yes. The 2012 USDA map put 91750 in zone 9b; the 2023 map puts it in zone 10a. The newer map uses 1991–2020 data and more weather stations.