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

Planting zone for 40312 — Clay City, KY

ZIP code 40312 (Clay City, Powell County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 19 and the first fall frost October 20.

Where ZIP 40312 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 19
First frostOct 20
2012 zone6b

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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Clay City, KY…

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 Clay City, KY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 5only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 10
Growing season184 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around October 30.

From the NOAA station Stanton 2w, KY — 2 miles away, elevation 722 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 40312

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 20) 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 40312 came on Mar 6 — 4 days earlier than the 1991–2020 average (Mar 10).

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 6b in Kentucky

531 plants native to the lower 48 states, recorded in Kentucky, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 76

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 107

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 177

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °F

Grasses 147

autumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °Fblister sedge3 ft · blooms late spring · medium shade tolerance · to −38 °Fbluejoint5 ft · blooms late spring · high shade tolerance · to −33 °F

Vines 12

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °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 Clay City, KY.

Soil in Clay City, KY

The soil mapped at the center of ZIP 40312 is Cotaco — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH4.6strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Cotaco silt loam, 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 40312; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Clay City, KY

Summer high84 °Faverage high, July
Winter low23 °Faverage low, January
Hot days13days a year at 90 °F or more
Freezing nights107nights a year at 32 °F or less
Growing degree days3,637base 50 °F — the season’s usable heat
Longest day14 h 47 mindaylight on June 21
Shortest day9 h 32 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation48.5 inper year, rain and melted snow
Snowfall6 inper year; 5 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 42 °F, low 23 °F 42°23° JanFebruary: average high 47 °F, low 26 °F 47°26° FebMarch: average high 56 °F, low 33 °F 56°33° MarApril: average high 67 °F, low 42 °F 67°42° AprMay: average high 75 °F, low 52 °F 75°52° MayJune: average high 82 °F, low 61 °F 82°61° JunJuly: average high 84 °F, low 64 °F 84°64° JulAugust: average high 83 °F, low 63 °F 83°63° AugSeptember: average high 79 °F, low 56 °F 79°56° SepOctober: average high 69 °F, low 43 °F 69°43° OctNovember: average high 57 °F, low 34 °F 57°34° NovDecember: average high 46 °F, low 28 °F 46°28° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 3.43 in precipitation, 2.8 in snowfall 3.4❄3 JanFebruary: 3.46 in precipitation, 2.3 in snowfall 3.5❄2 FebMarch: 4.18 in precipitation, 0.3 in snowfall 4.2 MarApril: 4.10 in precipitation, 0.1 in snowfall 4.1 AprMay: 5.39 in precipitation 5.4 MayJune: 4.20 in precipitation 4.2 JunJuly: 5.30 in precipitation 5.3 JulAugust: 3.95 in precipitation 4.0 AugSeptember: 3.78 in precipitation 3.8 SepOctober: 3.65 in precipitation 3.6 OctNovember: 3.19 in precipitation, 0.1 in snowfall 3.2 NovDecember: 3.92 in precipitation, 0.6 in snowfall 3.9❄1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Stanton 2w, KY (2 mi away); precipitation: Clay City 1 Wnw, KY (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

403807a
Stanton, KY · 8 mi
403376b
Jeffersonville, KY · 8 mi
404727a
Ravenna, KY · 9 mi
403366b
Irvine, KY · 12 mi
403767a
Slade, KY · 12 mi
403856b
Waco, KY · 13 mi
403467a
Means, KY · 14 mi
403916b
Winchester, KY · 14 mi

Kentucky planting zones →

Questions about 40312

What planting zone is ZIP code 40312?

ZIP code 40312 (Clay City, KY) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Clay City, KY?

The median last spring frost (32 °F) near 40312 is April 19; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Stanton 2w station.

When is the first frost in Clay City, KY?

The median first fall frost near 40312 is October 20, giving a median frost-free growing season of 184 days.

When should I plant tomatoes in 40312?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 40312 get?

About 48.5 inches of precipitation a year and 6 inches of snowfall (NOAA 1991–2020 normals, Clay City 1 Wnw station).

How hot do summers get in Clay City, KY?

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 40312 have?

The USDA soil survey maps Cotaco at the center of ZIP 40312: silt loam, moderately well drained, pH about 4.6 (strongly acidic).

Did spring come early in Clay City, KY in 2026?

Spring leaf-out near 40312 came on Mar 6 in 2026, 4 days earlier than the 1991–2020 average (Mar 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Clay City, KY?

Intermediate onions: the longest day near 40312 is 14 h 47 min, so day-neutral types bulb best; long-day varieties may not bulb fully.