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

Planting zone for 12418 — Cornwallville, NY

ZIP code 12418 (Cornwallville, Greene County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 29 and the first fall frost October 14.

Where ZIP 12418 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostApr 29
First frostOct 14
2012 zone5b

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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Cornwallville, NY…

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 Cornwallville, NY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 29median — 50% chance of a later frost
Safe for tender plantsMay 13only 10% chance of frost after
First fall frostOctober 14median — 10% chance by Oct 1
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 29.

From the NOAA station Cairo 3 Nw, NY — 7 miles away, elevation 489 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 12418

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 18 – Apr 1
SpinachSow outdoors · Mar 18 – Apr 8
Broccoli, cabbageStart indoors · Feb 18 – Mar 4
Broccoli, cabbageTransplant · Apr 8 – Apr 22
Onion setsPlant outdoors · Apr 1 – Apr 15
PotatoesPlant outdoors · Apr 8 – Apr 22
LettuceSow outdoors · Apr 1 – Apr 15
Carrots, beetsSow outdoors · Apr 8 – Apr 22
TomatoesStart indoors · Mar 4 – Mar 18
TomatoesTransplant · May 6 – May 20
Peppers, eggplantStart indoors · Feb 18 – Mar 4
Peppers, eggplantTransplant · May 13 – May 27
BeansSow outdoors · May 6 – May 20
Sweet cornSow outdoors · May 6 – May 20
Cucumbers, squashSow outdoors · May 6 – May 20
Fall lettuce, spinachSow outdoors · Aug 19 – Sep 2
GarlicPlant cloves · Sep 30 – Nov 4
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 14) 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 12418 came on Apr 11 — 4 days earlier than the 1991–2020 average (Apr 15).

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).

Native plants for zone 5b in New York

609 plants native to the lower 48 states, recorded in New York, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 75

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 120

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 208

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 185

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 7

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °Ftrumpet honeysuckle16 ft · blooms late summer · low shade tolerance · to −33 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Cornwallville, NY.

Soil in Cornwallville, NY

The soil mapped at the center of ZIP 12418 is Wellsboro — channery loam, moderately well drained.

TextureChannery loama good balance for most vegetables
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter5%high
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Wellsboro channery loam, 8 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 12418; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cornwallville, NY

Summer high84 °Faverage high, July
Winter low16 °Faverage low, January
Hot days13days a year at 90 °F or more
Freezing nights148nights a year at 32 °F or less
Growing degree days2,720base 50 °F — the season’s usable heat
Longest day15 h 17 mindaylight on June 21
Shortest day9 h 04 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation46.3 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 33 °F, low 16 °F 33°16° JanFebruary: average high 37 °F, low 17 °F 37°17° FebMarch: average high 45 °F, low 25 °F 45°25° MarApril: average high 59 °F, low 36 °F 59°36° AprMay: average high 71 °F, low 47 °F 71°47° MayJune: average high 79 °F, low 56 °F 79°56° JunJuly: average high 84 °F, low 60 °F 84°60° JulAugust: average high 82 °F, low 59 °F 82°59° AugSeptember: average high 75 °F, low 51 °F 75°51° SepOctober: average high 62 °F, low 40 °F 62°40° OctNovember: average high 50 °F, low 31 °F 50°31° NovDecember: average high 39 °F, low 23 °F 39°23° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.20 in precipitation 3.2 JanFebruary: 2.47 in precipitation 2.5 FebMarch: 3.76 in precipitation 3.8 MarApril: 3.85 in precipitation 3.9 AprMay: 3.69 in precipitation 3.7 MayJune: 4.89 in precipitation 4.9 JunJuly: 4.01 in precipitation 4.0 JulAugust: 4.37 in precipitation 4.4 AugSeptember: 4.46 in precipitation 4.5 SepOctober: 5.06 in precipitation 5.1 OctNovember: 3.10 in precipitation 3.1 NovDecember: 3.47 in precipitation 3.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cairo 3 Nw, NY (7 mi away); precipitation: Windham 3 E, NY (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

124235b
East Durham, NY · 3 mi
124225b
Durham, NY · 4 mi
124055b
Acra, NY · 5 mi
124605b
Oak Hill, NY · 5 mi
124545b
Maplecrest, NY · 5 mi
124965b
Windham, NY · 6 mi
124395b
Hensonville, NY · 6 mi
124705b
Purling, NY · 7 mi

New York planting zones →

Questions about 12418

What planting zone is ZIP code 12418?

ZIP code 12418 (Cornwallville, NY) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Cornwallville, NY?

The median last spring frost (32 °F) near 12418 is April 29; after May 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cairo 3 Nw station.

When is the first frost in Cornwallville, NY?

The median first fall frost near 12418 is October 14, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 12418?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 12418 get?

About 46.3 inches of precipitation a year (NOAA 1991–2020 normals, Windham 3 E station).

How hot do summers get in Cornwallville, NY?

The average high peaks at 84 °F in July, with about 13 days a year at 90 °F or more.

What kind of soil does 12418 have?

The USDA soil survey maps Wellsboro at the center of ZIP 12418: channery loam, moderately well drained, pH about 5.5 (moderately acidic).

Did spring come early in Cornwallville, NY in 2026?

Spring leaf-out near 12418 came on Apr 11 in 2026, 4 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cornwallville, NY?

Long-day onions: the longest day near 12418 is 15 h 17 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).