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

Planting zone for 93546 — Mammoth Lakes, CA

ZIP code 93546 (Mammoth Lakes, Mono County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is June 10 and the first fall frost September 17.

Where ZIP 93546 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostJun 10
First frostSep 17
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mammoth Lakes, 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 Mammoth Lakes, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 10median — 50% chance of a later frost
Safe for tender plantsJune 30only 10% chance of frost after
First fall frostSeptember 17median — 10% chance by Sep 2
Growing season98 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 31 and returns around October 1.

From the NOAA station Mammoth Lakes Rs, CA — 9 miles away, elevation 7,805 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 93546

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 29 – May 13
SpinachSow outdoors · Apr 29 – May 20
Broccoli, cabbageStart indoors · Apr 1 – Apr 15
Broccoli, cabbageTransplant · May 20 – Jun 3
Onion setsPlant outdoors · May 13 – May 27
PotatoesPlant outdoors · May 20 – Jun 3
LettuceSow outdoors · May 13 – May 27
Carrots, beetsSow outdoors · May 20 – Jun 3
TomatoesStart indoors · Apr 15 – Apr 29
TomatoesTransplant · Jun 17 – Jul 1
Peppers, eggplantStart indoors · Apr 1 – Apr 15
Peppers, eggplantTransplant · Jun 24 – Jul 8
BeansSow outdoors · Jun 17 – Jul 1
Sweet cornSow outdoors · Jun 17 – Jul 1
Cucumbers, squashSow outdoors · Jun 17 – Jul 1
Fall lettuce, spinachSow outdoors · Jul 23 – Aug 6
GarlicPlant cloves · Sep 3 – Oct 8
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 10) and first fall frost (Sep 17) 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 93546 came on Apr 26 — 22 days earlier than the 1991–2020 average (May 18).

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 Mammoth Lakes, CA

The soil mapped at the center of ZIP 93546 is Lithic Cryorthents — extremely stony sand, somewhat excessively drained.

TextureExtremely stony sanddrains and warms fast; dries out and needs more feeding
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Rock outcrop-Lithic cryothents-Nanamkin family association, 15 to 60 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 93546; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mammoth Lakes, CA

Summer high78 °Faverage high, July
Winter low17 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights210nights a year at 32 °F or less
Growing degree days1,322base 50 °F — the season’s usable heat
Longest day14 h 45 mindaylight on June 21
Shortest day9 h 34 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation23.7 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 41 °F, low 17 °F 41°17° JanFebruary: average high 41 °F, low 18 °F 41°18° FebMarch: average high 46 °F, low 22 °F 46°22° MarApril: average high 51 °F, low 27 °F 51°27° AprMay: average high 60 °F, low 35 °F 60°35° MayJune: average high 70 °F, low 42 °F 70°42° JunJuly: average high 78 °F, low 49 °F 78°49° JulAugust: average high 77 °F, low 47 °F 77°47° AugSeptember: average high 71 °F, low 40 °F 71°40° SepOctober: average high 61 °F, low 30 °F 61°30° OctNovember: average high 49 °F, low 23 °F 49°23° NovDecember: average high 41 °F, low 17 °F 41°17° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.20 in precipitation 4.2 JanFebruary: 3.77 in precipitation 3.8 FebMarch: 3.28 in precipitation 3.3 MarApril: 1.54 in precipitation 1.5 AprMay: 1.49 in precipitation 1.5 MayJune: 0.47 in precipitation 0.5 JunJuly: 0.51 in precipitation 0.5 JulAugust: 0.49 in precipitation 0.5 AugSeptember: 0.47 in precipitation 0.5 SepOctober: 1.43 in precipitation 1.4 OctNovember: 2.00 in precipitation 2.0 NovDecember: 4.07 in precipitation 4.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Mammoth Lakes Rs, CA (9 mi away); precipitation: Mammoth Lakes Rs, CA (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

936426a
Mono Hot Springs, CA · 18 mi
936345b
Lakeshore, CA · 24 mi
935296a
June Lake, CA · 25 mi
935147a
Bishop, CA · 25 mi
935158a
Bishop, CA · 28 mi
935126b
Benton, CA · 28 mi
936057b
Big Creek, CA · 34 mi
935416b
Lee Vining, CA · 35 mi

California planting zones →

Questions about 93546

What planting zone is ZIP code 93546?

ZIP code 93546 (Mammoth Lakes, CA) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Mammoth Lakes, CA?

The median last spring frost (32 °F) near 93546 is June 10; after June 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mammoth Lakes Rs station.

When is the first frost in Mammoth Lakes, CA?

The median first fall frost near 93546 is September 17, giving a median frost-free growing season of 98 days.

When should I plant tomatoes in 93546?

Start tomato seeds indoors around Apr 15 – Apr 29 and set transplants outside around Jun 17 – Jul 1, one to three weeks after the median last frost.

How much rain and snow does 93546 get?

About 23.7 inches of precipitation a year (NOAA 1991–2020 normals, Mammoth Lakes Rs station).

How hot do summers get in Mammoth Lakes, CA?

The average high peaks at 78 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 93546 have?

The USDA soil survey maps Lithic Cryorthents at the center of ZIP 93546: extremely stony sand, somewhat excessively drained, pH about 5.5 (moderately acidic).

Did spring come early in Mammoth Lakes, CA in 2026?

Spring leaf-out near 93546 came on Apr 26 in 2026, 22 days earlier than the 1991–2020 average (May 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mammoth Lakes, CA?

Intermediate onions: the longest day near 93546 is 14 h 45 min, so day-neutral types bulb best; long-day varieties may not bulb fully.