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

Planting zone for 91012 — La Canada Flintridge, CA

ZIP code 91012 (La Canada Flintridge, Los Angeles County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 91012 is

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 zone10a

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 10a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for La Canada Flintridge, 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 Pasadena, CA — 4 miles away, elevation 863 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 91012 came on Jan 17 — 4 days earlier than the 1991–2020 average (Jan 21).

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 Canada Flintridge, CA

The soil mapped at the center of ZIP 91012 is Soboba — sandy loam, excessively drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH6.8neutral; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Soboba-Tujunga complex, 5 to 15 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 91012; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in La Canada Flintridge, CA

Summer high91 °Faverage high, August
Winter low45 °Faverage low, December
Hot days74days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days5,867base 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
Precipitation21.4 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 46 °F 68°46° JanFebruary: average high 69 °F, low 46 °F 69°46° FebMarch: average high 73 °F, low 48 °F 73°48° MarApril: average high 76 °F, low 51 °F 76°51° AprMay: average high 78 °F, low 54 °F 78°54° MayJune: average high 84 °F, low 58 °F 84°58° JunJuly: average high 89 °F, low 62 °F 89°62° JulAugust: average high 91 °F, low 63 °F 91°63° AugSeptember: average high 90 °F, low 62 °F 90°62° SepOctober: average high 83 °F, low 56 °F 83°56° OctNovember: average high 75 °F, low 50 °F 75°50° NovDecember: average high 67 °F, low 45 °F 67°45° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 4.80 in precipitation 4.8 JanFebruary: 5.74 in precipitation 5.7 FebMarch: 3.19 in precipitation 3.2 MarApril: 1.29 in precipitation 1.3 AprMay: 0.74 in precipitation 0.7 MayJune: 0.21 in precipitation 0.2 JunJuly: 0.08 in precipitation 0.1 JulAugust: 0.01 in precipitation 0.0 AugSeptember: 0.18 in precipitation 0.2 SepOctober: 0.91 in precipitation 0.9 OctNovember: 1.18 in precipitation 1.2 NovDecember: 3.04 in precipitation 3.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Pasadena, CA (4 mi away); precipitation: Altadena, CA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

9101110a
La Canada Flintridge, CA · 2 mi
9102110a
Montrose, CA · 2 mi
9110310b
Pasadena, CA · 3 mi
9102010a
Montrose, CA · 3 mi
9100110b
Altadena, CA · 3 mi
9120610a
Glendale, CA · 3 mi
9120810a
Glendale, CA · 3 mi
9104610a
Verdugo City, CA · 3 mi

All 2 ZIP codes in La Canada Flintridge → · California planting zones →

Questions about 91012

What planting zone is ZIP code 91012?

ZIP code 91012 (La Canada Flintridge, 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 91012 get?

About 21.4 inches of precipitation a year (NOAA 1991–2020 normals, Altadena station).

How hot do summers get in La Canada Flintridge, CA?

The average high peaks at 91 °F in August, with about 74 days a year at 90 °F or more.

What kind of soil does 91012 have?

The USDA soil survey maps Soboba at the center of ZIP 91012: sandy loam, excessively drained, pH about 6.8 (neutral).

Did spring come early in La Canada Flintridge, CA in 2026?

Spring leaf-out near 91012 came on Jan 17 in 2026, 4 days earlier than the 1991–2020 average (Jan 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in La Canada Flintridge, CA?

Intermediate onions: the longest day near 91012 is 14 h 26 min, so day-neutral types bulb best; long-day varieties may not bulb fully.