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

Planting zone for 91358 — Thousand Oaks, CA

ZIP code 91358 (Thousand Oaks, Ventura County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 91358 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 Thousand Oaks, 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 Camarillo Airport, CA — 14 miles away, elevation 79 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 91358 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 Thousand Oaks, CA

The soil mapped at the center of ZIP 91358 is Rincon — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH7.6slightly alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classFarmland of local importanceUSDA classification

Map unit: Rincon silty clay loam, 9 to 15 percent slopes, eroded, warm MAAT, MLRA 19.

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 91358; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Thousand Oaks, CA

Summer high80 °Faverage high, August
Winter low44 °Faverage low, December
Hot days9days a year at 90 °F or more
Freezing nights1nights a year at 32 °F or less
Growing degree days4,589base 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
Precipitation16.1 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 68 °F, low 45 °F 68°45° JanFebruary: average high 68 °F, low 46 °F 68°46° FebMarch: average high 69 °F, low 47 °F 69°47° MarApril: average high 71 °F, low 49 °F 71°49° AprMay: average high 72 °F, low 53 °F 72°53° MayJune: average high 75 °F, low 57 °F 75°57° JunJuly: average high 78 °F, low 60 °F 78°60° JulAugust: average high 80 °F, low 61 °F 80°61° AugSeptember: average high 80 °F, low 59 °F 80°59° SepOctober: average high 76 °F, low 54 °F 76°54° OctNovember: average high 73 °F, low 49 °F 73°49° NovDecember: average high 68 °F, low 44 °F 68°44° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.73 in precipitation 3.7 JanFebruary: 4.14 in precipitation 4.1 FebMarch: 2.58 in precipitation 2.6 MarApril: 0.79 in precipitation 0.8 AprMay: 0.36 in precipitation 0.4 MayJune: 0.08 in precipitation 0.1 JunJuly: 0.05 in precipitation 0.1 JulAugust: 0.01 in precipitation 0.0 AugSeptember: 0.10 in precipitation 0.1 SepOctober: 0.74 in precipitation 0.7 OctNovember: 0.92 in precipitation 0.9 NovDecember: 2.60 in precipitation 2.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Camarillo Airport, CA (14 mi away); precipitation: Thousand Oaks 2.1 Wsw, CA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

9136210b
Thousand Oaks, CA · 2 mi
9135910a
Westlake Village, CA · 3 mi
9136110b
Westlake Village, CA · 3 mi
9136010a
Thousand Oaks, CA · 4 mi
9137710b
Oak Park, CA · 4 mi
9131910a
Newbury Park, CA · 4 mi
9137610a
Agoura Hills, CA · 4 mi
9130110b
Agoura Hills, CA · 6 mi

All 3 ZIP codes in Thousand Oaks → · California planting zones →

Questions about 91358

What planting zone is ZIP code 91358?

ZIP code 91358 (Thousand Oaks, 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 91358 get?

About 16.1 inches of precipitation a year (NOAA 1991–2020 normals, Thousand Oaks 2.1 Wsw station).

How hot do summers get in Thousand Oaks, CA?

The average high peaks at 80 °F in August, with about 9 days a year at 90 °F or more.

What kind of soil does 91358 have?

The USDA soil survey maps Rincon at the center of ZIP 91358: silty clay loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Thousand Oaks, CA in 2026?

Spring leaf-out near 91358 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 Thousand Oaks, CA?

Intermediate onions: the longest day near 91358 is 14 h 26 min, so day-neutral types bulb best; long-day varieties may not bulb fully.