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

Planting zone for 40107 — Boston, KY

ZIP code 40107 (Boston, Nelson County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 13 and the first fall frost October 25.

Where ZIP 40107 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 13

First frostOct 25

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 Boston, 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 Boston, KY

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 13median — 50% chance of a later frost

Safe for tender plantsMay 3only 10% chance of frost after

First fall frostOctober 25median — 10% chance by Oct 13

Growing season195 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 31 and returns around November 5.

From the NOAA station Bardstown 5e, KY — 14 miles away, elevation 781 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 40107

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 2 – Mar 16

SpinachSow outdoors · Mar 2 – Mar 23

Broccoli, cabbageStart indoors · Feb 2 – Feb 16

Broccoli, cabbageTransplant · Mar 23 – Apr 6

Onion setsPlant outdoors · Mar 16 – Mar 30

PotatoesPlant outdoors · Mar 23 – Apr 6

LettuceSow outdoors · Mar 16 – Mar 30

Carrots, beetsSow outdoors · Mar 23 – Apr 6

TomatoesStart indoors · Feb 16 – Mar 2

TomatoesTransplant · Apr 20 – May 4

Peppers, eggplantStart indoors · Feb 2 – Feb 16

Peppers, eggplantTransplant · Apr 27 – May 11

BeansSow outdoors · Apr 20 – May 4

Sweet cornSow outdoors · Apr 20 – May 4

Cucumbers, squashSow outdoors · Apr 20 – May 4

Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13

GarlicPlant cloves · Oct 11 – Nov 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 13) and first fall frost (Oct 25) 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 40107 came on Mar 2 — 6 days earlier than the 1991–2020 average (Mar 8).

average
Mar 82026
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).

Soil in Boston, KY

The soil mapped at the center of ZIP 40107 is Lenberg — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH4.5strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Lenberg silt loam, 20 to 50 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 40107; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Boston, KY

Summer high87 °Faverage high, July

Winter low26 °Faverage low, January

Hot days24days a year at 90 °F or more

Freezing nights87nights a year at 32 °F or less

Growing degree days4,157base 50 °F — the season’s usable heat

Longest day14 h 47 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

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: Bardstown 5e, KY (14 mi away); precipitation: New Haven 6.4 Ne, KY (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

Lebanon Junction, KY · 11 mi

400627a

Saint Francis, KY · 12 mi

400497a

Nerinx, KY · 12 mi

Kentucky planting zones →

Questions about 40107

What planting zone is ZIP code 40107?

ZIP code 40107 (Boston, 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 Boston, KY?

The median last spring frost (32 °F) near 40107 is April 13; after May 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bardstown 5e station.

When is the first frost in Boston, KY?

The median first fall frost near 40107 is October 25, giving a median frost-free growing season of 195 days.

When should I plant tomatoes in 40107?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 40107 get?

About 52.1 inches of precipitation a year (NOAA 1991–2020 normals, New Haven 6.4 Ne station).

How hot do summers get in Boston, KY?

The average high peaks at 87 °F in July, with about 24 days a year at 90 °F or more.

What kind of soil does 40107 have?

The USDA soil survey maps Lenberg at the center of ZIP 40107: silt loam, well drained, pH about 4.5 (strongly acidic).

Did spring come early in Boston, KY in 2026?

Spring leaf-out near 40107 came on Mar 2 in 2026, 6 days earlier than the 1991–2020 average (Mar 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Boston, KY?

Intermediate onions: the longest day near 40107 is 14 h 47 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 40107 change?

Yes. The 2012 USDA map put 40107 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.