Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 42377 — West Louisville, KY

ZIP code 42377 (West Louisville, Daviess County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 2 and the first fall frost November 1.

Where ZIP 42377 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.

Zone7a0 to 5 °F

Coldest night−17.8 to −15 °C

Last frostApr 2

First frostNov 1

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 West 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 West Louisville, KY

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 2median — 50% chance of a later frost

Safe for tender plantsApril 20only 10% chance of frost after

First fall frostNovember 1median — 10% chance by Oct 19

Growing season211 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 23 and returns around November 10.

From the NOAA station Calhoun Lock 2, KY — 11 miles away, elevation 404 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 42377

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 19 – Mar 5

SpinachSow outdoors · Feb 19 – Mar 12

Broccoli, cabbageStart indoors · Jan 22 – Feb 5

Broccoli, cabbageTransplant · Mar 12 – Mar 26

Onion setsPlant outdoors · Mar 5 – Mar 19

PotatoesPlant outdoors · Mar 12 – Mar 26

LettuceSow outdoors · Mar 5 – Mar 19

Carrots, beetsSow outdoors · Mar 12 – Mar 26

TomatoesStart indoors · Feb 5 – Feb 19

TomatoesTransplant · Apr 9 – Apr 23

Peppers, eggplantStart indoors · Jan 22 – Feb 5

Peppers, eggplantTransplant · Apr 16 – Apr 30

BeansSow outdoors · Apr 9 – Apr 23

Sweet cornSow outdoors · Apr 9 – Apr 23

Cucumbers, squashSow outdoors · Apr 9 – Apr 23

Fall lettuce, spinachSow outdoors · Sep 6 – Sep 20

GarlicPlant cloves · Oct 18 – Nov 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 2) and first fall frost (Nov 1) 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 42377 came on Mar 2 — 7 days earlier than the 1991–2020 average (Mar 9).

average
Mar 92026
Mar 2

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.

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 West Louisville, KY.

Soil in West Louisville, KY

The soil mapped at the center of ZIP 42377 is Alford — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH5.9moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Alford silt loam, 12 to 20 percent slopes, severely eroded.

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 42377; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in West Louisville, KY

Summer high87 °Faverage high, July

Winter low26 °Faverage low, January

Hot days34days a year at 90 °F or more

Freezing nights83nights a year at 32 °F or less

Growing degree days4,293base 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

Precipitation49.4 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Calhoun Lock 2, KY (11 mi away); precipitation: Owensboro 4.9 S, KY (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

423567a

Maple Mount, KY · 2 mi

423017a

Owensboro, KY · 3 mi

423347a

Curdsville, KY · 4 mi

423227a

Beech Grove, KY · 8 mi

423277a

Calhoun, KY · 8 mi

423027a

Owensboro, KY · 10 mi

423047a

Owensboro, KY · 10 mi

423767a

Utica, KY · 12 mi

Kentucky planting zones →

Questions about 42377

What planting zone is ZIP code 42377?

ZIP code 42377 (West 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 West Louisville, KY?

The median last spring frost (32 °F) near 42377 is April 2; after April 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Calhoun Lock 2 station.

When is the first frost in West Louisville, KY?

The median first fall frost near 42377 is November 1, giving a median frost-free growing season of 211 days.

When should I plant tomatoes in 42377?

Start tomato seeds indoors around Feb 5 – Feb 19 and set transplants outside around Apr 9 – Apr 23, one to three weeks after the median last frost.

How much rain and snow does 42377 get?

About 49.4 inches of precipitation a year (NOAA 1991–2020 normals, Owensboro 4.9 S station).

How hot do summers get in West Louisville, KY?

The average high peaks at 87 °F in July, with about 34 days a year at 90 °F or more.

What kind of soil does 42377 have?

The USDA soil survey maps Alford at the center of ZIP 42377: silt loam, well drained, pH about 5.9 (moderately acidic).

Did spring come early in West Louisville, KY in 2026?

Spring leaf-out near 42377 came on Mar 2 in 2026, 7 days earlier than the 1991–2020 average (Mar 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in West Louisville, KY?

Intermediate onions: the longest day near 42377 is 14 h 46 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 42377 change?

Yes. The 2012 USDA map put 42377 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.