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

Planting zone for 93920 — Big Sur, CA

ZIP code 93920 (Big Sur, Monterey County) is in USDA zone 10b: the coldest winter night averages 35 to 40 °F. The median last spring frost is February 13 and the first fall frost December 27.

Where ZIP 93920 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.

Zone10b35 to 40 °F
Coldest night1.7 to 4.4 °C
Last frostFeb 13
First frostDec 27
2012 zone9b

Was 9b on the 2012 map — a full zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 10b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Big Sur, 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 Big Sur, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 13median — 50% chance of a later frost
Safe for tender plantsApril 1only 10% chance of frost after
First fall frostDecember 27median — 10% chance by Nov 23
Growing season323 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 25 and returns around January 6.

From the NOAA station Big Sur Stn, CA — 20 miles away, elevation 200 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 93920

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 2 – Jan 16
SpinachSow outdoors · Jan 2 – Jan 23
Broccoli, cabbageStart indoors · Dec 5 – Dec 19
Broccoli, cabbageTransplant · Jan 23 – Feb 6
Onion setsPlant outdoors · Jan 16 – Jan 30
PotatoesPlant outdoors · Jan 23 – Feb 6
LettuceSow outdoors · Jan 16 – Jan 30
Carrots, beetsSow outdoors · Jan 23 – Feb 6
TomatoesStart indoors · Dec 19 – Jan 2
TomatoesTransplant · Feb 20 – Mar 6
Peppers, eggplantStart indoors · Dec 5 – Dec 19
Peppers, eggplantTransplant · Feb 27 – Mar 13
BeansSow outdoors · Feb 20 – Mar 6
Sweet cornSow outdoors · Feb 20 – Mar 6
Cucumbers, squashSow outdoors · Feb 20 – Mar 6
Fall lettuce, spinachSow outdoors · Nov 1 – Nov 15
GarlicPlant cloves · Dec 13 – Jan 17
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 13) and first fall frost (Dec 27) 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 93920 came on Jan 18 — 14 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 Big Sur, CA

The soil mapped at the center of ZIP 93920 is Cieneba — gravelly sandy loam, somewhat excessively drained.

TextureGravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH6.5neutral; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Cieneba-Sur-Rock outcrop complex.

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 93920; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Big Sur, CA

Summer high77 °Faverage high, August
Winter low42 °Faverage low, January
Hot days11days a year at 90 °F or more
Freezing nights3nights a year at 32 °F or less
Growing degree days2,885base 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
Precipitation17.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 61 °F, low 42 °F 61°42° JanFebruary: average high 61 °F, low 43 °F 61°43° FebMarch: average high 64 °F, low 43 °F 64°43° MarApril: average high 67 °F, low 44 °F 67°44° AprMay: average high 71 °F, low 46 °F 71°46° MayJune: average high 74 °F, low 48 °F 74°48° JunJuly: average high 75 °F, low 51 °F 75°51° JulAugust: average high 77 °F, low 50 °F 77°50° AugSeptember: average high 77 °F, low 50 °F 77°50° SepOctober: average high 74 °F, low 49 °F 74°49° OctNovember: average high 65 °F, low 45 °F 65°45° NovDecember: average high 59 °F, low 43 °F 59°43° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.16 in precipitation 4.2 JanFebruary: 3.74 in precipitation 3.7 FebMarch: 2.97 in precipitation 3.0 MarApril: 1.03 in precipitation 1.0 AprMay: 0.46 in precipitation 0.5 MayJune: 0.12 in precipitation 0.1 JunJuly: 0.06 in precipitation 0.1 JulAugust: 0.02 in precipitation 0.0 AugSeptember: 0.07 in precipitation 0.1 SepOctober: 0.63 in precipitation 0.6 OctNovember: 1.34 in precipitation 1.3 NovDecember: 2.66 in precipitation 2.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Big Sur Stn, CA (20 mi away); precipitation: King City 13.2 S, CA (19 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

939289a
Jolon, CA · 3 mi
939279b
Greenfield, CA · 17 mi
939329a
Lockwood, CA · 26 mi
939249b
Carmel Valley, CA · 26 mi
939309a
King City, CA · 26 mi
939609b
Soledad, CA · 27 mi
9345210a
San Simeon, CA · 27 mi
9392310a
Carmel, CA · 29 mi

California planting zones →

Questions about 93920

What planting zone is ZIP code 93920?

ZIP code 93920 (Big Sur, CA) is in USDA hardiness zone 10b on the 2023 map: the coldest night of an average winter reaches 35 to 40 °F (1.7 to 4.4 °C).

When is the last frost in Big Sur, CA?

The median last spring frost (32 °F) near 93920 is February 13; after April 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Big Sur Stn station.

When is the first frost in Big Sur, CA?

The median first fall frost near 93920 is December 27, giving a median frost-free growing season of 323 days.

When should I plant tomatoes in 93920?

Start tomato seeds indoors around Dec 19 – Jan 2 and set transplants outside around Feb 20 – Mar 6, one to three weeks after the median last frost.

How much rain and snow does 93920 get?

About 17.3 inches of precipitation a year (NOAA 1991–2020 normals, King City 13.2 S station).

How hot do summers get in Big Sur, CA?

The average high peaks at 77 °F in August, with about 11 days a year at 90 °F or more.

What kind of soil does 93920 have?

The USDA soil survey maps Cieneba at the center of ZIP 93920: gravelly sandy loam, somewhat excessively drained, pH about 6.5 (neutral).

Did spring come early in Big Sur, CA in 2026?

Spring leaf-out near 93920 came on Jan 18 in 2026, 14 days earlier than the 1991–2020 average (Feb 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Big Sur, CA?

Intermediate onions: the longest day near 93920 is 14 h 37 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 93920 change?

Yes. The 2012 USDA map put 93920 in zone 9b; the 2023 map puts it in zone 10b. The newer map uses 1991–2020 data and more weather stations.