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

Planting zone for 40336 — Irvine, KY

ZIP code 40336 (Irvine, Estill County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 20 and the first fall frost October 19.

Where ZIP 40336 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 20
First frostOct 19
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 Irvine, 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 Irvine, KY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 20median — 50% chance of a later frost
Safe for tender plantsMay 8only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 8
Growing season182 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around October 30.

From the NOAA station Cressy, KY — 11 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 40336

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 9 – Mar 23
SpinachSow outdoors · Mar 9 – Mar 30
Broccoli, cabbageStart indoors · Feb 9 – Feb 23
Broccoli, cabbageTransplant · Mar 30 – Apr 13
Onion setsPlant outdoors · Mar 23 – Apr 6
PotatoesPlant outdoors · Mar 30 – Apr 13
LettuceSow outdoors · Mar 23 – Apr 6
Carrots, beetsSow outdoors · Mar 30 – Apr 13
TomatoesStart indoors · Feb 23 – Mar 9
TomatoesTransplant · Apr 27 – May 11
Peppers, eggplantStart indoors · Feb 9 – Feb 23
Peppers, eggplantTransplant · May 4 – May 18
BeansSow outdoors · Apr 27 – May 11
Sweet cornSow outdoors · Apr 27 – May 11
Cucumbers, squashSow outdoors · Apr 27 – May 11
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 20) and first fall frost (Oct 19) 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 40336 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).

Soil in Irvine, KY

The soil mapped at the center of ZIP 40336 is Morehead — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH5.4strongly acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2%moderate
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Morehead silt loam, 0 to 2 percent slopes, rarely flooded.

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 40336; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Irvine, KY

Summer high85 °Faverage high, July
Winter low23 °Faverage low, January
Hot days18days a year at 90 °F or more
Freezing nights116nights a year at 32 °F or less
Growing degree days3,664base 50 °F — the season’s usable heat
Longest day14 h 46 mindaylight on June 21
Shortest day9 h 33 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation50.9 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 23 °F 43°23° JanFebruary: average high 48 °F, low 25 °F 48°25° FebMarch: average high 57 °F, low 32 °F 57°32° MarApril: average high 68 °F, low 41 °F 68°41° AprMay: average high 76 °F, low 52 °F 76°52° MayJune: average high 83 °F, low 61 °F 83°61° JunJuly: average high 85 °F, low 65 °F 85°65° JulAugust: average high 85 °F, low 62 °F 85°62° AugSeptember: average high 79 °F, low 55 °F 79°55° SepOctober: average high 69 °F, low 42 °F 69°42° OctNovember: average high 57 °F, low 32 °F 57°32° NovDecember: average high 47 °F, low 28 °F 47°28° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.58 in precipitation 3.6 JanFebruary: 3.69 in precipitation 3.7 FebMarch: 4.73 in precipitation 4.7 MarApril: 4.57 in precipitation 4.6 AprMay: 5.40 in precipitation 5.4 MayJune: 4.90 in precipitation 4.9 JunJuly: 5.42 in precipitation 5.4 JulAugust: 3.66 in precipitation 3.7 AugSeptember: 3.94 in precipitation 3.9 SepOctober: 3.54 in precipitation 3.5 OctNovember: 3.32 in precipitation 3.3 NovDecember: 4.15 in precipitation 4.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cressy, KY (11 mi away); precipitation: Cressy, KY (11 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.

404727a
Ravenna, KY · 8 mi
403856b
Waco, KY · 9 mi
403126b
Clay City, KY · 12 mi
403807a
Stanton, KY · 14 mi
404886b
Waneta, KY · 15 mi
404056b
Bighill, KY · 15 mi
413116b
Beattyville, KY · 16 mi
403767a
Slade, KY · 17 mi

Kentucky planting zones →

Questions about 40336

What planting zone is ZIP code 40336?

ZIP code 40336 (Irvine, 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 Irvine, KY?

The median last spring frost (32 °F) near 40336 is April 20; after May 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cressy station.

When is the first frost in Irvine, KY?

The median first fall frost near 40336 is October 19, giving a median frost-free growing season of 182 days.

When should I plant tomatoes in 40336?

Start tomato seeds indoors around Feb 23 – Mar 9 and set transplants outside around Apr 27 – May 11, one to three weeks after the median last frost.

How much rain and snow does 40336 get?

About 50.9 inches of precipitation a year (NOAA 1991–2020 normals, Cressy station).

How hot do summers get in Irvine, KY?

The average high peaks at 85 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 40336 have?

The USDA soil survey maps Morehead at the center of ZIP 40336: silt loam, somewhat poorly drained, pH about 5.4 (strongly acidic).

Did spring come early in Irvine, KY in 2026?

Spring leaf-out near 40336 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 Irvine, KY?

Intermediate onions: the longest day near 40336 is 14 h 46 min, so day-neutral types bulb best; long-day varieties may not bulb fully.