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

Planting zone for 93550 — Palmdale, CA

ZIP code 93550 (Palmdale, Los Angeles County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 13 and the first fall frost December 1.

Where ZIP 93550 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 13

First frostDec 1

2012 zone8b

Was 8b 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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Palmdale, 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 Palmdale, CA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 13median — 50% chance of a later frost

Safe for tender plantsApril 17only 10% chance of frost after

First fall frostDecember 1median — 10% chance by Nov 12

Growing season258 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 9 and returns around December 12.

From the NOAA station Pearblossom, CA — 11 miles away, elevation 3,101 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 93550

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 30 – Feb 13

SpinachSow outdoors · Jan 30 – Feb 20

Broccoli, cabbageStart indoors · Jan 2 – Jan 16

Broccoli, cabbageTransplant · Feb 20 – Mar 6

Onion setsPlant outdoors · Feb 13 – Feb 27

PotatoesPlant outdoors · Feb 20 – Mar 6

LettuceSow outdoors · Feb 13 – Feb 27

Carrots, beetsSow outdoors · Feb 20 – Mar 6

TomatoesStart indoors · Jan 16 – Jan 30

TomatoesTransplant · Mar 20 – Apr 3

Peppers, eggplantStart indoors · Jan 2 – Jan 16

Peppers, eggplantTransplant · Mar 27 – Apr 10

BeansSow outdoors · Mar 20 – Apr 3

Sweet cornSow outdoors · Mar 20 – Apr 3

Cucumbers, squashSow outdoors · Mar 20 – Apr 3

Fall lettuce, spinachSow outdoors · Oct 6 – Oct 20

GarlicPlant cloves · Nov 17 – Dec 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 13) and first fall frost (Dec 1) 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 93550 came on Jan 29 — 13 days earlier than the 1991–2020 average (Feb 11).

average
Feb 112026
Jan 29

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 Palmdale, CA

The soil mapped at the center of ZIP 93550 is Pismo family — gravelly loamy sand, somewhat excessively drained.

TextureGravelly loamy sanddrains and warms fast; dries out and needs more feeding

pH6.6neutral; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter1%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Pismo-Trigo, dry-Exchequer, dry families complex, 30 to 70 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 93550; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Palmdale, CA

Summer high99 °Faverage high, July

Winter low36 °Faverage low, December

Hot days107days a year at 90 °F or more

Freezing nights26nights a year at 32 °F or less

Growing degree days5,595base 50 °F — the season’s usable heat

Longest day14 h 27 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

Precipitation24.8 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: Pearblossom, CA (11 mi away); precipitation: Big Tujunga Dam Fc46, CA (11 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.

935438b

Littlerock, CA · 7 mi

935538b

Pearblossom, CA · 10 mi

Mount Wilson, CA · 13 mi

9104210a

Tujunga, CA · 13 mi

All 6 ZIP codes in Palmdale → · California planting zones →

Questions about 93550

What planting zone is ZIP code 93550?

ZIP code 93550 (Palmdale, 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 Palmdale, CA?

The median last spring frost (32 °F) near 93550 is March 13; after April 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Pearblossom station.

When is the first frost in Palmdale, CA?

The median first fall frost near 93550 is December 1, giving a median frost-free growing season of 258 days.

When should I plant tomatoes in 93550?

Start tomato seeds indoors around Jan 16 – Jan 30 and set transplants outside around Mar 20 – Apr 3, one to three weeks after the median last frost.

How much rain and snow does 93550 get?

About 24.8 inches of precipitation a year (NOAA 1991–2020 normals, Big Tujunga Dam Fc46 station).

How hot do summers get in Palmdale, CA?

The average high peaks at 99 °F in July, with about 107 days a year at 90 °F or more.

What kind of soil does 93550 have?

The USDA soil survey maps Pismo family at the center of ZIP 93550: gravelly loamy sand, somewhat excessively drained, pH about 6.6 (neutral).

Did spring come early in Palmdale, CA in 2026?

Spring leaf-out near 93550 came on Jan 29 in 2026, 13 days earlier than the 1991–2020 average (Feb 11), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Palmdale, CA?

Intermediate onions: the longest day near 93550 is 14 h 27 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 93550 change?

Yes. The 2012 USDA map put 93550 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.