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

Planting zone for 42159 — Oakland, KY

ZIP code 42159 (Oakland, Warren County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 12 and the first fall frost October 29.

Where ZIP 42159 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 12

First frostOct 29

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 Oakland, 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 Oakland, KY

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 12median — 50% chance of a later frost

Safe for tender plantsApril 30only 10% chance of frost after

First fall frostOctober 29median — 10% chance by Oct 16

Growing season198 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 31 and returns around November 6.

From the NOAA station Barren Rvr Lake, KY — 10 miles away, elevation 617 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 42159

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 1 – Mar 15

SpinachSow outdoors · Mar 1 – Mar 22

Broccoli, cabbageStart indoors · Feb 1 – Feb 15

Broccoli, cabbageTransplant · Mar 22 – Apr 5

Onion setsPlant outdoors · Mar 15 – Mar 29

PotatoesPlant outdoors · Mar 22 – Apr 5

LettuceSow outdoors · Mar 15 – Mar 29

Carrots, beetsSow outdoors · Mar 22 – Apr 5

TomatoesStart indoors · Feb 15 – Mar 1

TomatoesTransplant · Apr 19 – May 3

Peppers, eggplantStart indoors · Feb 1 – Feb 15

Peppers, eggplantTransplant · Apr 26 – May 10

BeansSow outdoors · Apr 19 – May 3

Sweet cornSow outdoors · Apr 19 – May 3

Cucumbers, squashSow outdoors · Apr 19 – May 3

Fall lettuce, spinachSow outdoors · Sep 3 – Sep 17

GarlicPlant cloves · Oct 15 – Nov 19

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 12) and first fall frost (Oct 29) 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 42159 came on Mar 2 — about the same time as the 1991–2020 average (Mar 4).

average
Mar 42026
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 Oakland, KY.

Soil in Oakland, KY

The soil mapped at the center of ZIP 42159 is Baxter — gravelly silt loam, well drained.

TextureGravelly silt loama good balance for most vegetables

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupBwater soaks in moderately

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Baxter gravelly silt loam, 6 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 42159; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Oakland, KY

Summer high88 °Faverage high, July

Winter low26 °Faverage low, January

Hot days58days a year at 90 °F or more

Freezing nights88nights a year at 32 °F or less

Growing degree days4,338base 50 °F — the season’s usable heat

Longest day14 h 42 mindaylight on June 21

Shortest day9 h 37 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation52.1 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: Barren Rvr Lake, KY (10 mi away); precipitation: Smiths Grove 0.3 Se, KY (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

421037a

Bowling Green, KY · 5 mi

421717a

Smiths Grove, KY · 5 mi

421287a

Drake, KY · 8 mi

421637a

Rocky Hill, KY · 9 mi

421027a

Bowling Green, KY · 9 mi

421227a

Alvaton, KY · 11 mi

421607a

Park City, KY · 12 mi

421017a

Bowling Green, KY · 13 mi

Kentucky planting zones →

Questions about 42159

What planting zone is ZIP code 42159?

ZIP code 42159 (Oakland, 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 Oakland, KY?

The median last spring frost (32 °F) near 42159 is April 12; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Barren Rvr Lake station.

When is the first frost in Oakland, KY?

The median first fall frost near 42159 is October 29, giving a median frost-free growing season of 198 days.

When should I plant tomatoes in 42159?

Start tomato seeds indoors around Feb 15 – Mar 1 and set transplants outside around Apr 19 – May 3, one to three weeks after the median last frost.

How much rain and snow does 42159 get?

About 52.1 inches of precipitation a year (NOAA 1991–2020 normals, Smiths Grove 0.3 Se station).

How hot do summers get in Oakland, KY?

The average high peaks at 88 °F in July, with about 58 days a year at 90 °F or more.

What kind of soil does 42159 have?

The USDA soil survey maps Baxter at the center of ZIP 42159: gravelly silt loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Oakland, KY in 2026?

Spring leaf-out near 42159 came on Mar 2 in 2026, about the same as the 1991–2020 average (Mar 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Oakland, KY?

Intermediate onions: the longest day near 42159 is 14 h 42 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 42159 change?

Yes. The 2012 USDA map put 42159 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.