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

Planting zone for 40220 — Louisville, KY

ZIP code 40220 (Louisville, Jefferson County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 3 and the first fall frost November 3.

Where ZIP 40220 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 3
First frostNov 3
2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Louisville, 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 Louisville, KY

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 3median — 50% chance of a later frost
Safe for tender plantsApril 19only 10% chance of frost after
First fall frostNovember 3median — 10% chance by Oct 21
Growing season214 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 22 and returns around November 13.

From the NOAA station Louisville Bowman Field, KY — 2 miles away, elevation 541 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 40220

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 20 – Mar 6
SpinachSow outdoors · Feb 20 – Mar 13
Broccoli, cabbageStart indoors · Jan 23 – Feb 6
Broccoli, cabbageTransplant · Mar 13 – Mar 27
Onion setsPlant outdoors · Mar 6 – Mar 20
PotatoesPlant outdoors · Mar 13 – Mar 27
LettuceSow outdoors · Mar 6 – Mar 20
Carrots, beetsSow outdoors · Mar 13 – Mar 27
TomatoesStart indoors · Feb 6 – Feb 20
TomatoesTransplant · Apr 10 – Apr 24
Peppers, eggplantStart indoors · Jan 23 – Feb 6
Peppers, eggplantTransplant · Apr 17 – May 1
BeansSow outdoors · Apr 10 – Apr 24
Sweet cornSow outdoors · Apr 10 – Apr 24
Cucumbers, squashSow outdoors · Apr 10 – Apr 24
Fall lettuce, spinachSow outdoors · Sep 8 – Sep 22
GarlicPlant cloves · Oct 20 – Nov 24
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 3) and first fall frost (Nov 3) 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 40220 came on Mar 3 — 6 days earlier than the 1991–2020 average (Mar 9).

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 7a in Kentucky

547 plants native to the lower 48 states, recorded in Kentucky, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 78

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 109

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 181

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 153

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 14

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fcupseed30 ft · blooms late spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °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 Louisville, KY.

Soil in Louisville, KY

The soil mapped at the center of ZIP 40220 is Crider — silt loam, well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSilt loama good balance for most vegetables
pH5.6moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Alfic Udarents-Crider complex, 0 to 12 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 40220; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Louisville, KY

Summer high88 °Faverage high, July
Winter low27 °Faverage low, January
Hot days38days a year at 90 °F or more
Freezing nights80nights a year at 32 °F or less
Growing degree days4,455base 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
Precipitation48.1 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 27 °F 43°27° JanFebruary: average high 48 °F, low 30 °F 48°30° FebMarch: average high 57 °F, low 38 °F 57°38° MarApril: average high 69 °F, low 48 °F 69°48° AprMay: average high 77 °F, low 57 °F 77°57° MayJune: average high 85 °F, low 66 °F 85°66° JunJuly: average high 88 °F, low 69 °F 88°69° JulAugust: average high 87 °F, low 68 °F 87°68° AugSeptember: average high 81 °F, low 60 °F 81°60° SepOctober: average high 69 °F, low 48 °F 69°48° OctNovember: average high 57 °F, low 38 °F 57°38° NovDecember: average high 46 °F, low 31 °F 46°31° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.28 in precipitation 3.3 JanFebruary: 3.27 in precipitation 3.3 FebMarch: 4.37 in precipitation 4.4 MarApril: 4.69 in precipitation 4.7 AprMay: 5.16 in precipitation 5.2 MayJune: 4.68 in precipitation 4.7 JunJuly: 4.56 in precipitation 4.6 JulAugust: 3.53 in precipitation 3.5 AugSeptember: 3.61 in precipitation 3.6 SepOctober: 3.65 in precipitation 3.6 OctNovember: 3.44 in precipitation 3.4 NovDecember: 3.88 in precipitation 3.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Louisville Bowman Field, KY (2 mi away); precipitation: Louisville Bowman Field, KY (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

402187a
Louisville, KY · 3 mi
402227a
Louisville, KY · 3 mi
402057a
Louisville, KY · 4 mi
402017a
Louisville, KY · 4 mi
402247a
Louisville, KY · 4 mi
402257a
Louisville, KY · 4 mi
402327a
Louisville, KY · 4 mi
402337a
Louisville, KY · 4 mi

All 65 ZIP codes in Louisville → · Kentucky planting zones →

Questions about 40220

What planting zone is ZIP code 40220?

ZIP code 40220 (Louisville, KY) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Louisville, KY?

The median last spring frost (32 °F) near 40220 is April 3; after April 19 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Louisville Bowman Field station.

When is the first frost in Louisville, KY?

The median first fall frost near 40220 is November 3, giving a median frost-free growing season of 214 days.

When should I plant tomatoes in 40220?

Start tomato seeds indoors around Feb 6 – Feb 20 and set transplants outside around Apr 10 – Apr 24, one to three weeks after the median last frost.

How much rain and snow does 40220 get?

About 48.1 inches of precipitation a year (NOAA 1991–2020 normals, Louisville Bowman Field station).

How hot do summers get in Louisville, KY?

The average high peaks at 88 °F in July, with about 38 days a year at 90 °F or more.

What kind of soil does 40220 have?

The USDA soil survey maps Crider at the center of ZIP 40220: silt loam, well drained, pH about 5.6 (moderately acidic).

Did spring come early in Louisville, KY in 2026?

Spring leaf-out near 40220 came on Mar 3 in 2026, 6 days earlier than the 1991–2020 average (Mar 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Louisville, KY?

Intermediate onions: the longest day near 40220 is 14 h 50 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 40220 change?

Yes. The 2012 USDA map put 40220 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.