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

Planting zone for 40604 — Frankfort, KY

ZIP code 40604 (Frankfort, Franklin County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 15 and the first fall frost October 24.

Where ZIP 40604 is

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 15
First frostOct 24
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 Frankfort, 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 Frankfort, KY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 15median — 50% chance of a later frost
Safe for tender plantsMay 5only 10% chance of frost after
First fall frostOctober 24median — 10% chance by Oct 13
Growing season192 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 3 and returns around November 4.

From the NOAA station Frankfort Capital City Airport, KY — 4 miles away, elevation 804 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 40604

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 4 – Mar 18
SpinachSow outdoors · Mar 4 – Mar 25
Broccoli, cabbageStart indoors · Feb 4 – Feb 18
Broccoli, cabbageTransplant · Mar 25 – Apr 8
Onion setsPlant outdoors · Mar 18 – Apr 1
PotatoesPlant outdoors · Mar 25 – Apr 8
LettuceSow outdoors · Mar 18 – Apr 1
Carrots, beetsSow outdoors · Mar 25 – Apr 8
TomatoesStart indoors · Feb 18 – Mar 4
TomatoesTransplant · Apr 22 – May 6
Peppers, eggplantStart indoors · Feb 4 – Feb 18
Peppers, eggplantTransplant · Apr 29 – May 13
BeansSow outdoors · Apr 22 – May 6
Sweet cornSow outdoors · Apr 22 – May 6
Cucumbers, squashSow outdoors · Apr 22 – May 6
Fall lettuce, spinachSow outdoors · Aug 29 – Sep 12
GarlicPlant cloves · Oct 10 – Nov 14
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 15) and first fall frost (Oct 24) 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 40604 came on Mar 7 — 8 days earlier than the 1991–2020 average (Mar 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 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 Frankfort, KY.

Soil in Frankfort, KY

The soil mapped at the center of ZIP 40604 is Faywood — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Faywood silt loam, 12 to 30 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 40604; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Frankfort, KY

Summer high88 °Faverage high, July
Winter low25 °Faverage low, January
Hot days28days a year at 90 °F or more
Freezing nights98nights a year at 32 °F or less
Growing degree days4,141base 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
Precipitation50.5 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 25 °F 43°25° JanFebruary: average high 48 °F, low 28 °F 48°28° FebMarch: average high 57 °F, low 35 °F 57°35° MarApril: average high 69 °F, low 45 °F 69°45° AprMay: average high 77 °F, low 54 °F 77°54° MayJune: average high 85 °F, low 63 °F 85°63° JunJuly: average high 88 °F, low 67 °F 88°67° JulAugust: average high 87 °F, low 65 °F 87°65° AugSeptember: average high 81 °F, low 57 °F 81°57° SepOctober: average high 70 °F, low 46 °F 70°46° OctNovember: average high 57 °F, low 36 °F 57°36° NovDecember: average high 47 °F, low 29 °F 47°29° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.59 in precipitation 3.6 JanFebruary: 3.58 in precipitation 3.6 FebMarch: 4.62 in precipitation 4.6 MarApril: 4.77 in precipitation 4.8 AprMay: 5.19 in precipitation 5.2 MayJune: 4.83 in precipitation 4.8 JunJuly: 5.44 in precipitation 5.4 JulAugust: 3.65 in precipitation 3.6 AugSeptember: 3.47 in precipitation 3.5 SepOctober: 3.63 in precipitation 3.6 OctNovember: 3.63 in precipitation 3.6 NovDecember: 4.12 in precipitation 4.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Frankfort Capital City Airport, KY (4 mi away); precipitation: Frankfort 1.9 N, KY (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

406026b
Frankfort, KY · <1 mi
406036b
Frankfort, KY · <1 mi
406186b
Frankfort, KY · <1 mi
406196b
Frankfort, KY · <1 mi
406206b
Frankfort, KY · <1 mi
406016b
Frankfort, KY · <1 mi
406216b
Frankfort, KY · 2 mi
406226b
Frankfort, KY · 2 mi

All 9 ZIP codes in Frankfort → · Kentucky planting zones →

Questions about 40604

What planting zone is ZIP code 40604?

ZIP code 40604 (Frankfort, 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 Frankfort, KY?

The median last spring frost (32 °F) near 40604 is April 15; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Frankfort Capital City Airport station.

When is the first frost in Frankfort, KY?

The median first fall frost near 40604 is October 24, giving a median frost-free growing season of 192 days.

When should I plant tomatoes in 40604?

Start tomato seeds indoors around Feb 18 – Mar 4 and set transplants outside around Apr 22 – May 6, one to three weeks after the median last frost.

How much rain and snow does 40604 get?

About 50.5 inches of precipitation a year (NOAA 1991–2020 normals, Frankfort 1.9 N station).

How hot do summers get in Frankfort, KY?

The average high peaks at 88 °F in July, with about 28 days a year at 90 °F or more.

What kind of soil does 40604 have?

The USDA soil survey maps Faywood at the center of ZIP 40604: silt loam, well drained, pH about 6.5 (neutral).

Did spring come early in Frankfort, KY in 2026?

Spring leaf-out near 40604 came on Mar 7 in 2026, 8 days earlier than the 1991–2020 average (Mar 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Frankfort, KY?

Intermediate onions: the longest day near 40604 is 14 h 50 min, so day-neutral types bulb best; long-day varieties may not bulb fully.