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

Planting zone for 95246 — Mountain Ranch, CA

ZIP code 95246 (Mountain Ranch, Calaveras County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is May 7 and the first fall frost October 28.

Where ZIP 95246 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 7
First frostOct 28
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 Mountain Ranch, 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 Mountain Ranch, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 7median — 50% chance of a later frost
Safe for tender plantsMay 31only 10% chance of frost after
First fall frostOctober 28median — 10% chance by Oct 5
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around November 14.

From the NOAA station Calaveras Big Trees, CA — 10 miles away, elevation 4,695 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 95246

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 26 – Apr 9
SpinachSow outdoors · Mar 26 – Apr 16
Broccoli, cabbageStart indoors · Feb 26 – Mar 12
Broccoli, cabbageTransplant · Apr 16 – Apr 30
Onion setsPlant outdoors · Apr 9 – Apr 23
PotatoesPlant outdoors · Apr 16 – Apr 30
LettuceSow outdoors · Apr 9 – Apr 23
Carrots, beetsSow outdoors · Apr 16 – Apr 30
TomatoesStart indoors · Mar 12 – Mar 26
TomatoesTransplant · May 14 – May 28
Peppers, eggplantStart indoors · Feb 26 – Mar 12
Peppers, eggplantTransplant · May 21 – Jun 4
BeansSow outdoors · May 14 – May 28
Sweet cornSow outdoors · May 14 – May 28
Cucumbers, squashSow outdoors · May 14 – May 28
Fall lettuce, spinachSow outdoors · Sep 2 – Sep 16
GarlicPlant cloves · Oct 14 – Nov 18
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 7) and first fall frost (Oct 28) 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 95246 came on Jan 25 — 11 days earlier than the 1991–2020 average (Feb 5).

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 Mountain Ranch, CA

The soil mapped at the center of ZIP 95246 is Iron Mountain — gravelly sandy loam, somewhat excessively drained.

TextureGravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH6.3slightly acidic; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter5%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Iron Mountain-Rock outcrop complex, 3 to 15 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 95246; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mountain Ranch, CA

Summer high81 °Faverage high, July
Winter low30 °Faverage low, January
Hot days2days a year at 90 °F or more
Freezing nights115nights a year at 32 °F or less
Growing degree days2,183base 50 °F — the season’s usable heat
Longest day14 h 50 mindaylight on June 21
Shortest day9 h 30 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation40.6 inper year, rain and melted snow
Snowfall4 inper year; 1 days with snow on the ground

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 45 °F, low 30 °F 45°30° JanFebruary: average high 46 °F, low 30 °F 46°30° FebMarch: average high 49 °F, low 32 °F 49°32° MarApril: average high 54 °F, low 35 °F 54°35° AprMay: average high 63 °F, low 42 °F 63°42° MayJune: average high 73 °F, low 49 °F 73°49° JunJuly: average high 81 °F, low 56 °F 81°56° JulAugust: average high 80 °F, low 55 °F 80°55° AugSeptember: average high 74 °F, low 51 °F 74°51° SepOctober: average high 64 °F, low 43 °F 64°43° OctNovember: average high 52 °F, low 34 °F 52°34° NovDecember: average high 44 °F, low 30 °F 44°30° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″8″January: 7.34 in precipitation, 0.1 in snowfall 7.3 JanFebruary: 6.91 in precipitation, 1.7 in snowfall 6.9❄2 FebMarch: 6.39 in precipitation, 1.5 in snowfall 6.4❄2 MarApril: 3.36 in precipitation 3.4 AprMay: 2.14 in precipitation 2.1 MayJune: 0.49 in precipitation 0.5 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.27 in precipitation 0.3 SepOctober: 2.15 in precipitation 2.1 OctNovember: 3.95 in precipitation 4.0 NovDecember: 7.52 in precipitation, 0.4 in snowfall 7.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Calaveras Big Trees, CA (10 mi away); precipitation: W Pt, CA (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

952489a
Rail Road Flat, CA · 5 mi
952459a
Mokelumne Hill, CA · 7 mi
952338b
Hathaway Pines, CA · 8 mi
952499a
San Andreas, CA · 8 mi
952479a
Murphys, CA · 8 mi
952329a
Glencoe, CA · 9 mi
952578b
Wilseyville, CA · 9 mi
952248b
Avery, CA · 9 mi

California planting zones →

Questions about 95246

What planting zone is ZIP code 95246?

ZIP code 95246 (Mountain Ranch, 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 Mountain Ranch, CA?

The median last spring frost (32 °F) near 95246 is May 7; after May 31 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Calaveras Big Trees station.

When is the first frost in Mountain Ranch, CA?

The median first fall frost near 95246 is October 28, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 95246?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 95246 get?

About 40.6 inches of precipitation a year and 4 inches of snowfall (NOAA 1991–2020 normals, W Pt station).

How hot do summers get in Mountain Ranch, CA?

The average high peaks at 81 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 95246 have?

The USDA soil survey maps Iron Mountain at the center of ZIP 95246: gravelly sandy loam, somewhat excessively drained, pH about 6.3 (slightly acidic).

Did spring come early in Mountain Ranch, CA in 2026?

Spring leaf-out near 95246 came on Jan 25 in 2026, 11 days earlier than the 1991–2020 average (Feb 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mountain Ranch, CA?

Intermediate onions: the longest day near 95246 is 14 h 50 min, so day-neutral types bulb best; long-day varieties may not bulb fully.