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

Planting zone for 93432 — Creston, CA

ZIP code 93432 (Creston, San Luis Obispo County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 15 and the first fall frost November 10.

Where ZIP 93432 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.

Zone8b15 to 20 °F
Coldest night−9.4 to −6.7 °C
Last frostMar 15
First frostNov 10
2012 zone9a

Was 9a on the 2012 map — half a zone colder now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Creston, 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 Creston, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 15median — 50% chance of a later frost
Safe for tender plantsApril 13only 10% chance of frost after
First fall frostNovember 10median — 10% chance by Oct 23
Growing season238 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 9 and returns around November 26.

From the NOAA station Paso Robles, CA — 16 miles away, elevation 732 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 93432

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 1 – Feb 15
SpinachSow outdoors · Feb 1 – Feb 22
Broccoli, cabbageStart indoors · Jan 4 – Jan 18
Broccoli, cabbageTransplant · Feb 22 – Mar 8
Onion setsPlant outdoors · Feb 15 – Mar 1
PotatoesPlant outdoors · Feb 22 – Mar 8
LettuceSow outdoors · Feb 15 – Mar 1
Carrots, beetsSow outdoors · Feb 22 – Mar 8
TomatoesStart indoors · Jan 18 – Feb 1
TomatoesTransplant · Mar 22 – Apr 5
Peppers, eggplantStart indoors · Jan 4 – Jan 18
Peppers, eggplantTransplant · Mar 29 – Apr 12
BeansSow outdoors · Mar 22 – Apr 5
Sweet cornSow outdoors · Mar 22 – Apr 5
Cucumbers, squashSow outdoors · Mar 22 – Apr 5
Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29
GarlicPlant cloves · Oct 27 – Dec 1
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 15) and first fall frost (Nov 10) 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 93432 came on Jan 25 — 7 days earlier than the 1991–2020 average (Feb 1).

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 Creston, CA

The soil mapped at the center of ZIP 93432 is Balcom — loam, well drained.

TextureLoama good balance for most vegetables
pH8.2alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Balcom-Nacimiento association, moderately steep.

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 93432; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Creston, CA

Summer high92 °Faverage high, August
Winter low33 °Faverage low, December
Hot days80days a year at 90 °F or more
Freezing nights54nights a year at 32 °F or less
Growing degree days3,887base 50 °F — the season’s usable heat
Longest day14 h 33 mindaylight on June 21
Shortest day9 h 45 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation22.3 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 62 °F, low 34 °F 62°34° JanFebruary: average high 64 °F, low 37 °F 64°37° FebMarch: average high 68 °F, low 40 °F 68°40° MarApril: average high 73 °F, low 41 °F 73°41° AprMay: average high 80 °F, low 46 °F 80°46° MayJune: average high 87 °F, low 50 °F 87°50° JunJuly: average high 91 °F, low 53 °F 91°53° JulAugust: average high 92 °F, low 53 °F 92°53° AugSeptember: average high 89 °F, low 50 °F 89°50° SepOctober: average high 81 °F, low 43 °F 81°43° OctNovember: average high 69 °F, low 37 °F 69°37° NovDecember: average high 61 °F, low 33 °F 61°33° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 5.11 in precipitation 5.1 JanFebruary: 5.02 in precipitation 5.0 FebMarch: 3.89 in precipitation 3.9 MarApril: 1.40 in precipitation 1.4 AprMay: 0.52 in precipitation 0.5 MayJune: 0.06 in precipitation 0.1 JunJuly: 0.04 in precipitation 0.0 JulAugust: 0.01 in precipitation 0.0 AugSeptember: 0.09 in precipitation 0.1 SepOctober: 1.03 in precipitation 1.0 OctNovember: 1.55 in precipitation 1.6 NovDecember: 3.60 in precipitation 3.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Paso Robles, CA (16 mi away); precipitation: Salinas Dam, CA (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

934229a
Atascadero, CA · 12 mi
934659a
Templeton, CA · 15 mi
934109b
San Luis Obispo, CA · 16 mi
934079b
San Luis Obispo, CA · 16 mi
934618b
Shandon, CA · 16 mi
934099b
San Luis Obispo, CA · 16 mi
9340310a
San Luis Obispo, CA · 17 mi
9340610a
San Luis Obispo, CA · 17 mi

California planting zones →

Questions about 93432

What planting zone is ZIP code 93432?

ZIP code 93432 (Creston, CA) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Creston, CA?

The median last spring frost (32 °F) near 93432 is March 15; after April 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Paso Robles station.

When is the first frost in Creston, CA?

The median first fall frost near 93432 is November 10, giving a median frost-free growing season of 238 days.

When should I plant tomatoes in 93432?

Start tomato seeds indoors around Jan 18 – Feb 1 and set transplants outside around Mar 22 – Apr 5, one to three weeks after the median last frost.

How much rain and snow does 93432 get?

About 22.3 inches of precipitation a year (NOAA 1991–2020 normals, Salinas Dam station).

How hot do summers get in Creston, CA?

The average high peaks at 92 °F in August, with about 80 days a year at 90 °F or more.

What kind of soil does 93432 have?

The USDA soil survey maps Balcom at the center of ZIP 93432: loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Creston, CA in 2026?

Spring leaf-out near 93432 came on Jan 25 in 2026, 7 days earlier than the 1991–2020 average (Feb 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Creston, CA?

Intermediate onions: the longest day near 93432 is 14 h 33 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 93432 change?

Yes. The 2012 USDA map put 93432 in zone 9a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.