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

Planting zone for 93454 — Santa Maria, CA

ZIP code 93454 (Santa Maria, Santa Barbara County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 4 and the first fall frost December 4.

Where ZIP 93454 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.

Zone9b25 to 30 °F
Coldest night−3.9 to −1.1 °C
Last frostFeb 4
First frostDec 4
2012 zone9b

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 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Santa Maria, 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 Santa Maria, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 4median — 50% chance of a later frost
Safe for tender plantsMarch 31only 10% chance of frost after
First fall frostDecember 4median — 10% chance by Nov 14
Growing season301 daysfrost-free, median

A hard freeze (28 °F) usually ends around December 31 and returns around December 17.

From the NOAA station Twitchell Dam, CA — 6 miles away, elevation 581 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 93454

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 24 – Jan 7
SpinachSow outdoors · Dec 24 – Jan 14
Broccoli, cabbageStart indoors · Nov 26 – Dec 10
Broccoli, cabbageTransplant · Jan 14 – Jan 28
Onion setsPlant outdoors · Jan 7 – Jan 21
PotatoesPlant outdoors · Jan 14 – Jan 28
LettuceSow outdoors · Jan 7 – Jan 21
Carrots, beetsSow outdoors · Jan 14 – Jan 28
TomatoesStart indoors · Dec 10 – Dec 24
TomatoesTransplant · Feb 11 – Feb 25
Peppers, eggplantStart indoors · Nov 26 – Dec 10
Peppers, eggplantTransplant · Feb 18 – Mar 4
BeansSow outdoors · Feb 11 – Feb 25
Sweet cornSow outdoors · Feb 11 – Feb 25
Cucumbers, squashSow outdoors · Feb 11 – Feb 25
Fall lettuce, spinachSow outdoors · Oct 9 – Oct 23
GarlicPlant cloves · Nov 20 – Dec 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 4) and first fall frost (Dec 4) 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 93454 came on Jan 17 — 9 days earlier than the 1991–2020 average (Jan 26).

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 Santa Maria, CA

The soil mapped at the center of ZIP 93454 is Lopez — gravelly clay loam, somewhat excessively drained.

TextureGravelly clay loamholds water and nutrients; slow to drain and warm up
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter6%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Lopez gravelly clay loam, 15 to 75 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 93454; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Santa Maria, CA

Summer high78 °Faverage high, August
Winter low39 °Faverage low, December
Hot days26days a year at 90 °F or more
Freezing nights15nights a year at 32 °F or less
Growing degree days3,267base 50 °F — the season’s usable heat
Longest day14 h 30 mindaylight on June 21
Shortest day9 h 48 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation18.2 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 63 °F, low 41 °F 63°41° JanFebruary: average high 63 °F, low 43 °F 63°43° FebMarch: average high 65 °F, low 44 °F 65°44° MarApril: average high 68 °F, low 45 °F 68°45° AprMay: average high 70 °F, low 48 °F 70°48° MayJune: average high 75 °F, low 50 °F 75°50° JunJuly: average high 77 °F, low 53 °F 77°53° JulAugust: average high 78 °F, low 54 °F 78°54° AugSeptember: average high 78 °F, low 52 °F 78°52° SepOctober: average high 75 °F, low 49 °F 75°49° OctNovember: average high 68 °F, low 44 °F 68°44° NovDecember: average high 61 °F, low 39 °F 61°39° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.04 in precipitation 4.0 JanFebruary: 3.43 in precipitation 3.4 FebMarch: 3.25 in precipitation 3.3 MarApril: 1.47 in precipitation 1.5 AprMay: 0.55 in precipitation 0.6 MayJune: 0.10 in precipitation 0.1 JunJuly: 0.04 in precipitation 0.0 JulAugust: 0.01 in precipitation 0.0 AugSeptember: 0.07 in precipitation 0.1 SepOctober: 0.88 in precipitation 0.9 OctNovember: 1.40 in precipitation 1.4 NovDecember: 2.96 in precipitation 3.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Twitchell Dam, CA (6 mi away); precipitation: Twitchell Dam, CA (6 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.

934569b
Santa Maria, CA · 10 mi
934579b
Santa Maria, CA · 10 mi
934409b
Los Alamos, CA · 11 mi
934589b
Santa Maria, CA · 13 mi
934559b
Santa Maria, CA · 14 mi
934449b
Nipomo, CA · 16 mi
9344110a
Los Olivos, CA · 16 mi
9342910a
Casmalia, CA · 16 mi

All 5 ZIP codes in Santa Maria → · California planting zones →

Questions about 93454

What planting zone is ZIP code 93454?

ZIP code 93454 (Santa Maria, CA) is in USDA hardiness zone 9b on the 2023 map: the coldest night of an average winter reaches 25 to 30 °F (−3.9 to −1.1 °C).

When is the last frost in Santa Maria, CA?

The median last spring frost (32 °F) near 93454 is February 4; after March 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Twitchell Dam station.

When is the first frost in Santa Maria, CA?

The median first fall frost near 93454 is December 4, giving a median frost-free growing season of 301 days.

When should I plant tomatoes in 93454?

Start tomato seeds indoors around Dec 10 – Dec 24 and set transplants outside around Feb 11 – Feb 25, one to three weeks after the median last frost.

How much rain and snow does 93454 get?

About 18.2 inches of precipitation a year (NOAA 1991–2020 normals, Twitchell Dam station).

How hot do summers get in Santa Maria, CA?

The average high peaks at 78 °F in August, with about 26 days a year at 90 °F or more.

What kind of soil does 93454 have?

The USDA soil survey maps Lopez at the center of ZIP 93454: gravelly clay loam, somewhat excessively drained, pH about 5.8 (moderately acidic).

Did spring come early in Santa Maria, CA in 2026?

Spring leaf-out near 93454 came on Jan 17 in 2026, 9 days earlier than the 1991–2020 average (Jan 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Santa Maria, CA?

Intermediate onions: the longest day near 93454 is 14 h 30 min, so day-neutral types bulb best; long-day varieties may not bulb fully.