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

Planting zone for 93517 — Bridgeport, CA

ZIP code 93517 (Bridgeport, Mono County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 23 and the first fall frost October 9.

Where ZIP 93517 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 frostMay 23
First frostOct 9
2012 zone5b

Was 5b on the 2012 map — half a zone warmer now. 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 Bridgeport, 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 Bridgeport, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 23median — 50% chance of a later frost
Safe for tender plantsJune 9only 10% chance of frost after
First fall frostOctober 9median — 10% chance by Sep 27
Growing season139 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 2 and returns around October 21.

From the NOAA station Lee Vining, CA — 24 miles away, elevation 6,798 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 93517

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 11 – Apr 25
SpinachSow outdoors · Apr 11 – May 2
Broccoli, cabbageStart indoors · Mar 14 – Mar 28
Broccoli, cabbageTransplant · May 2 – May 16
Onion setsPlant outdoors · Apr 25 – May 9
PotatoesPlant outdoors · May 2 – May 16
LettuceSow outdoors · Apr 25 – May 9
Carrots, beetsSow outdoors · May 2 – May 16
TomatoesStart indoors · Mar 28 – Apr 11
TomatoesTransplant · May 30 – Jun 13
Peppers, eggplantStart indoors · Mar 14 – Mar 28
Peppers, eggplantTransplant · Jun 6 – Jun 20
BeansSow outdoors · May 30 – Jun 13
Sweet cornSow outdoors · May 30 – Jun 13
Cucumbers, squashSow outdoors · May 30 – Jun 13
Fall lettuce, spinachSow outdoors · Aug 14 – Aug 28
GarlicPlant cloves · Sep 25 – Oct 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 23) and first fall frost (Oct 9) 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 93517 came on Mar 21 — 23 days earlier than the 1991–2020 average (Apr 13).

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 Bridgeport, CA

The soil mapped at the center of ZIP 93517 is Patididit — ashy fine sandy loam, somewhat poorly drained.

TextureAshy fine sandy loamdrains and warms fast; dries out and needs more feeding
pH7.4slightly alkaline; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter0.75%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Patididit-Twojayay complex, 0 to 2 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 93517; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bridgeport, CA

Summer high85 °Faverage high, July
Winter low10 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights243nights a year at 32 °F or less
Growing degree days1,372base 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
Precipitation10.2 inper year, rain and melted snow
Snowfall32 inper year

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 10 °F 43°10° JanFebruary: average high 45 °F, low 13 °F 45°13° FebMarch: average high 52 °F, low 20 °F 52°20° MarApril: average high 59 °F, low 25 °F 59°25° AprMay: average high 67 °F, low 32 °F 67°32° MayJune: average high 77 °F, low 39 °F 77°39° JunJuly: average high 85 °F, low 43 °F 85°43° JulAugust: average high 84 °F, low 41 °F 84°41° AugSeptember: average high 78 °F, low 34 °F 78°34° SepOctober: average high 67 °F, low 24 °F 67°24° OctNovember: average high 55 °F, low 17 °F 55°17° NovDecember: average high 45 °F, low 12 °F 45°12° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 2.01 in precipitation, 7.4 in snowfall 2.0❄7 JanFebruary: 1.48 in precipitation, 8.2 in snowfall 1.5❄8 FebMarch: 0.87 in precipitation, 3.9 in snowfall 0.9❄4 MarApril: 0.62 in precipitation, 2.4 in snowfall 0.6❄2 AprMay: 0.68 in precipitation, 0.8 in snowfall 0.7❄1 MayJune: 0.44 in precipitation, 0.1 in snowfall 0.4 JunJuly: 0.48 in precipitation 0.5 JulAugust: 0.39 in precipitation 0.4 AugSeptember: 0.23 in precipitation 0.2 SepOctober: 0.70 in precipitation, 0.3 in snowfall 0.7 OctNovember: 0.78 in precipitation, 1.5 in snowfall 0.8❄2 NovDecember: 1.51 in precipitation, 7.3 in snowfall 1.5❄7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bridgeport, CA (3 mi away); precipitation: Bridgeport, CA (3 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.

961076b
Coleville, CA · 17 mi
935416b
Lee Vining, CA · 21 mi
953646b
Pinecrest, CA · 27 mi
961337a
Topaz, CA · 27 mi
894157a
Hawthorne, NV · 31 mi
952236b
Arnold, CA · 31 mi
894446b
Wellington, NV · 32 mi
935296a
June Lake, CA · 35 mi

California planting zones →

Questions about 93517

What planting zone is ZIP code 93517?

ZIP code 93517 (Bridgeport, 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 Bridgeport, CA?

The median last spring frost (32 °F) near 93517 is May 23; after June 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lee Vining station.

When is the first frost in Bridgeport, CA?

The median first fall frost near 93517 is October 9, giving a median frost-free growing season of 139 days.

When should I plant tomatoes in 93517?

Start tomato seeds indoors around Mar 28 – Apr 11 and set transplants outside around May 30 – Jun 13, one to three weeks after the median last frost.

How much rain and snow does 93517 get?

About 10.2 inches of precipitation a year and 32 inches of snowfall (NOAA 1991–2020 normals, Bridgeport station).

How hot do summers get in Bridgeport, CA?

The average high peaks at 85 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 93517 have?

The USDA soil survey maps Patididit at the center of ZIP 93517: ashy fine sandy loam, somewhat poorly drained, pH about 7.4 (slightly alkaline).

Did spring come early in Bridgeport, CA in 2026?

Spring leaf-out near 93517 came on Mar 21 in 2026, 23 days earlier than the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bridgeport, CA?

Intermediate onions: the longest day near 93517 is 14 h 50 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 93517 change?

Yes. The 2012 USDA map put 93517 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.