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

Planting zone for 93429 — Casmalia, CA

ZIP code 93429 (Casmalia, Santa Barbara County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F. The median last spring frost is February 4 and the first fall frost December 13.

Where ZIP 93429 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.

Zone10a30 to 35 °F
Coldest night−1.1 to 1.7 °C
Last frostFeb 4
First frostDec 13
2012 zone9b

Was 9b 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 10a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Casmalia, 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 Casmalia, 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 16only 10% chance of frost after
First fall frostDecember 13median — 10% chance by Nov 21
Growing season315 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 5 and returns around December 27.

From the NOAA station Santa Maria Public Airport, CA — 6 miles away, elevation 243 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 93429

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 18 – Nov 1
GarlicPlant cloves · Nov 29 – Jan 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 4) and first fall frost (Dec 13) 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 93429 came on Jan 18 — 7 days earlier than the 1991–2020 average (Jan 25).

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 Casmalia, CA

The soil mapped at the center of ZIP 93429 is Gazos — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Gazos clay loam, 30 to 45 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 93429; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Casmalia, CA

Summer high75 °Faverage high, September
Winter low40 °Faverage low, December
Hot days6days a year at 90 °F or more
Freezing nights9nights a year at 32 °F or less
Growing degree days3,257base 50 °F — the season’s usable heat
Longest day14 h 30 mindaylight on June 21
Shortest day9 h 49 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation13.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 65 °F, low 41 °F 65°41° JanFebruary: average high 65 °F, low 43 °F 65°43° FebMarch: average high 66 °F, low 44 °F 66°44° MarApril: average high 68 °F, low 45 °F 68°45° AprMay: average high 69 °F, low 49 °F 69°49° MayJune: average high 71 °F, low 52 °F 71°52° JunJuly: average high 73 °F, low 55 °F 73°55° JulAugust: average high 74 °F, low 55 °F 74°55° AugSeptember: average high 75 °F, low 54 °F 75°54° SepOctober: average high 75 °F, low 50 °F 75°50° OctNovember: average high 70 °F, low 44 °F 70°44° NovDecember: average high 64 °F, low 40 °F 64°40° Dec

Precipitation by month inches

0″1″2″3″January: 2.74 in precipitation 2.7 JanFebruary: 2.85 in precipitation 2.9 FebMarch: 2.56 in precipitation 2.6 MarApril: 0.93 in precipitation 0.9 AprMay: 0.36 in precipitation 0.4 MayJune: 0.06 in precipitation 0.1 JunJuly: 0.03 in precipitation 0.0 JulAugust: 0.01 in precipitation 0.0 AugSeptember: 0.07 in precipitation 0.1 SepOctober: 0.54 in precipitation 0.5 OctNovember: 1.12 in precipitation 1.1 NovDecember: 2.05 in precipitation 2.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Santa Maria Public Airport, CA (6 mi away); precipitation: Santa Maria Public Airport, CA (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

934559b
Santa Maria, CA · 3 mi
934589b
Santa Maria, CA · 6 mi
9343410a
Guadalupe, CA · 7 mi
9343710a
Lompoc, CA · 8 mi
934569b
Santa Maria, CA · 8 mi
934579b
Santa Maria, CA · 8 mi
934449b
Nipomo, CA · 12 mi
9344510a
Oceano, CA · 13 mi

California planting zones →

Questions about 93429

What planting zone is ZIP code 93429?

ZIP code 93429 (Casmalia, 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).

When is the last frost in Casmalia, CA?

The median last spring frost (32 °F) near 93429 is February 4; after March 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Santa Maria Public Airport station.

When is the first frost in Casmalia, CA?

The median first fall frost near 93429 is December 13, giving a median frost-free growing season of 315 days.

When should I plant tomatoes in 93429?

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 93429 get?

About 13.3 inches of precipitation a year (NOAA 1991–2020 normals, Santa Maria Public Airport station).

How hot do summers get in Casmalia, CA?

The average high peaks at 75 °F in September, with about 6 days a year at 90 °F or more.

What kind of soil does 93429 have?

The USDA soil survey maps Gazos at the center of ZIP 93429: clay loam, well drained, pH about 6.1 (slightly acidic).

Did spring come early in Casmalia, CA in 2026?

Spring leaf-out near 93429 came on Jan 18 in 2026, 7 days earlier than the 1991–2020 average (Jan 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Casmalia, CA?

Intermediate onions: the longest day near 93429 is 14 h 30 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 93429 change?

Yes. The 2012 USDA map put 93429 in zone 9b; the 2023 map puts it in zone 10a. The newer map uses 1991–2020 data and more weather stations.