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

Planting zone for 93450 — San Ardo, CA

ZIP code 93450 (San Ardo, Monterey County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is May 8 and the first fall frost October 22.

Where ZIP 93450 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 frostMay 8
First frostOct 22
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 San Ardo, 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 San Ardo, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 8median — 50% chance of a later frost
Safe for tender plantsMay 29only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 1
Growing season165 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around November 5.

From the NOAA station Priest Valley, CA — 10 miles away, elevation 2,300 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 93450

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 27 – Apr 10
SpinachSow outdoors · Mar 27 – Apr 17
Broccoli, cabbageStart indoors · Feb 27 – Mar 13
Broccoli, cabbageTransplant · Apr 17 – May 1
Onion setsPlant outdoors · Apr 10 – Apr 24
PotatoesPlant outdoors · Apr 17 – May 1
LettuceSow outdoors · Apr 10 – Apr 24
Carrots, beetsSow outdoors · Apr 17 – May 1
TomatoesStart indoors · Mar 13 – Mar 27
TomatoesTransplant · May 15 – May 29
Peppers, eggplantStart indoors · Feb 27 – Mar 13
Peppers, eggplantTransplant · May 22 – Jun 5
BeansSow outdoors · May 15 – May 29
Sweet cornSow outdoors · May 15 – May 29
Cucumbers, squashSow outdoors · May 15 – May 29
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 8) and first fall frost (Oct 22) 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 93450 came on Jan 28 — about the same time as the 1991–2020 average (Jan 30).

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 San Ardo, CA

The soil mapped at the center of ZIP 93450 is Shedd — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH8.2alkaline; 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: Shedd silt loam, 30 to 75 percent slopes, severely eroded.

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 93450; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in San Ardo, CA

Summer high96 °Faverage high, July
Winter low30 °Faverage low, January
Hot days92days a year at 90 °F or more
Freezing nights104nights a year at 32 °F or less
Growing degree days3,412base 50 °F — the season’s usable heat
Longest day14 h 37 mindaylight on June 21
Shortest day9 h 42 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation20.8 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 59 °F, low 30 °F 59°30° JanFebruary: average high 60 °F, low 33 °F 60°33° FebMarch: average high 65 °F, low 34 °F 65°34° MarApril: average high 71 °F, low 35 °F 71°35° AprMay: average high 79 °F, low 41 °F 79°41° MayJune: average high 89 °F, low 46 °F 89°46° JunJuly: average high 96 °F, low 51 °F 96°51° JulAugust: average high 96 °F, low 51 °F 96°51° AugSeptember: average high 91 °F, low 47 °F 91°47° SepOctober: average high 79 °F, low 39 °F 79°39° OctNovember: average high 66 °F, low 32 °F 66°32° NovDecember: average high 58 °F, low 30 °F 58°30° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.94 in precipitation 4.9 JanFebruary: 4.19 in precipitation 4.2 FebMarch: 3.69 in precipitation 3.7 MarApril: 1.34 in precipitation 1.3 AprMay: 0.67 in precipitation 0.7 MayJune: 0.06 in precipitation 0.1 JunJuly: 0.09 in precipitation 0.1 JulAugust: 0.02 in precipitation 0.0 AugSeptember: 0.05 in precipitation 0.1 SepOctober: 0.88 in precipitation 0.9 OctNovember: 1.42 in precipitation 1.4 NovDecember: 3.45 in precipitation 3.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Priest Valley, CA (10 mi away); precipitation: Priest Valley, CA (10 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.

939549a
San Lucas, CA · 8 mi
939329a
Lockwood, CA · 15 mi
939309a
King City, CA · 17 mi
934518b
San Miguel, CA · 18 mi
934269a
Bradley, CA · 19 mi
932109b
Coalinga, CA · 22 mi
934479a
Paso Robles, CA · 24 mi
934469a
Paso Robles, CA · 30 mi

California planting zones →

Questions about 93450

What planting zone is ZIP code 93450?

ZIP code 93450 (San Ardo, 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 San Ardo, CA?

The median last spring frost (32 °F) near 93450 is May 8; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Priest Valley station.

When is the first frost in San Ardo, CA?

The median first fall frost near 93450 is October 22, giving a median frost-free growing season of 165 days.

When should I plant tomatoes in 93450?

Start tomato seeds indoors around Mar 13 – Mar 27 and set transplants outside around May 15 – May 29, one to three weeks after the median last frost.

How much rain and snow does 93450 get?

About 20.8 inches of precipitation a year (NOAA 1991–2020 normals, Priest Valley station).

How hot do summers get in San Ardo, CA?

The average high peaks at 96 °F in July, with about 92 days a year at 90 °F or more.

What kind of soil does 93450 have?

The USDA soil survey maps Shedd at the center of ZIP 93450: silt loam, well drained, pH about 8.2 (alkaline).

Did spring come early in San Ardo, CA in 2026?

Spring leaf-out near 93450 came on Jan 28 in 2026, about the same as the 1991–2020 average (Jan 30), according to the USA National Phenology Network Spring Index.

What kind of onions grow in San Ardo, CA?

Intermediate onions: the longest day near 93450 is 14 h 37 min, so day-neutral types bulb best; long-day varieties may not bulb fully.