Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 93510 — Acton, CA

ZIP code 93510 (Acton, Los Angeles County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 10 and the first fall frost November 19.

Where ZIP 93510 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.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostMar 10

First frostNov 19

2012 zone9a

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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Acton, 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 in Acton, CA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMarch 10median — 50% chance of a later frost

Safe for tender plantsApril 11only 10% chance of frost after

First fall frostNovember 19median — 10% chance by Nov 3

Growing season248 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 13 and returns around December 1.

From the NOAA station Palmdale, CA — 12 miles away, elevation 2,612 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 93510

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 27 – Feb 10

SpinachSow outdoors · Jan 27 – Feb 17

Broccoli, cabbageStart indoors · Dec 30 – Jan 13

Broccoli, cabbageTransplant · Feb 17 – Mar 3

Onion setsPlant outdoors · Feb 10 – Feb 24

PotatoesPlant outdoors · Feb 17 – Mar 3

LettuceSow outdoors · Feb 10 – Feb 24

Carrots, beetsSow outdoors · Feb 17 – Mar 3

TomatoesStart indoors · Jan 13 – Jan 27

TomatoesTransplant · Mar 17 – Mar 31

Peppers, eggplantStart indoors · Dec 30 – Jan 13

Peppers, eggplantTransplant · Mar 24 – Apr 7

BeansSow outdoors · Mar 17 – Mar 31

Sweet cornSow outdoors · Mar 17 – Mar 31

Cucumbers, squashSow outdoors · Mar 17 – Mar 31

Fall lettuce, spinachSow outdoors · Sep 24 – Oct 8

GarlicPlant cloves · Nov 5 – Dec 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 10) and first fall frost (Nov 19) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 93510 came on Jan 23 — 9 days earlier than the 1991–2020 average (Feb 1).

average
Feb 12026
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 Acton, CA

The soil mapped at the center of ZIP 93510 is Las Posas — loam, well drained.

TextureLoama good balance for most vegetables

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Las Posas-Toomes rocky loams, 30 to 50 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 93510; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Acton, CA

Summer high98 °Faverage high, July

Winter low34 °Faverage low, December

Hot days118days a year at 90 °F or more

Freezing nights38nights a year at 32 °F or less

Growing degree days5,415base 50 °F — the season’s usable heat

Longest day14 h 28 mindaylight on June 21

Shortest day9 h 51 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation10.9 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Palmdale, CA (12 mi away); precipitation: Acton Escondido Fc261, CA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

913879b

Canyon Country, CA · 8 mi

Canyon Country, CA · 13 mi

California planting zones →

Questions about 93510

What planting zone is ZIP code 93510?

ZIP code 93510 (Acton, CA) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Acton, CA?

The median last spring frost (32 °F) near 93510 is March 10; after April 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Palmdale station.

When is the first frost in Acton, CA?

The median first fall frost near 93510 is November 19, giving a median frost-free growing season of 248 days.

When should I plant tomatoes in 93510?

Start tomato seeds indoors around Jan 13 – Jan 27 and set transplants outside around Mar 17 – Mar 31, one to three weeks after the median last frost.

How much rain and snow does 93510 get?

About 10.9 inches of precipitation a year (NOAA 1991–2020 normals, Acton Escondido Fc261 station).

How hot do summers get in Acton, CA?

The average high peaks at 98 °F in July, with about 118 days a year at 90 °F or more.

What kind of soil does 93510 have?

The USDA soil survey maps Las Posas at the center of ZIP 93510: loam, well drained, pH about 6.7 (neutral).

Did spring come early in Acton, CA in 2026?

Spring leaf-out near 93510 came on Jan 23 in 2026, 9 days earlier than the 1991–2020 average (Feb 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Acton, CA?

Intermediate onions: the longest day near 93510 is 14 h 28 min, so day-neutral types bulb best; long-day varieties may not bulb fully.