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

Planting zone for 46144 — Gwynneville, IN

ZIP code 46144 (Gwynneville, Shelby County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 19 and the first fall frost October 22.

Where ZIP 46144 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 19
First frostOct 22
2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Gwynneville, IN…

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 Gwynneville, IN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 7only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 9
Growing season185 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around November 1.

From the NOAA station Greenfield, IN — 11 miles away, elevation 869 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 46144

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 19) and first fall frost (Oct 22) 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 46144 came on Mar 10 — 16 days earlier than the 1991–2020 average (Mar 26).

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 6a in Indiana

558 plants native to the lower 48 states, recorded in Indiana, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 71

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 105

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 200

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °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 °F

Grasses 161

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 9

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 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low 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 Gwynneville, IN.

Soil in Gwynneville, IN

The soil mapped at the center of ZIP 46144 is Crosby — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH5.9moderately acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2.5%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Crosby silt loam, New Castle Till Plain, 0 to 2 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 46144; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Gwynneville, IN

Summer high84 °Faverage high, July
Winter low19 °Faverage low, January
Hot days16days a year at 90 °F or more
Freezing nights119nights a year at 32 °F or less
Growing degree days3,388base 50 °F — the season’s usable heat
Longest day14 h 59 mindaylight on June 21
Shortest day9 h 22 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation44.9 inper year, rain and melted snow
Snowfall20 inper year; 20 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 19 °F 35°19° JanFebruary: average high 39 °F, low 22 °F 39°22° FebMarch: average high 50 °F, low 30 °F 50°30° MarApril: average high 62 °F, low 41 °F 62°41° AprMay: average high 73 °F, low 52 °F 73°52° MayJune: average high 81 °F, low 61 °F 81°61° JunJuly: average high 84 °F, low 64 °F 84°64° JulAugust: average high 83 °F, low 62 °F 83°62° AugSeptember: average high 78 °F, low 55 °F 78°55° SepOctober: average high 65 °F, low 43 °F 65°43° OctNovember: average high 51 °F, low 33 °F 51°33° NovDecember: average high 39 °F, low 24 °F 39°24° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″6″January: 3.23 in precipitation, 7 in snowfall 3.2❄7 JanFebruary: 2.22 in precipitation, 5.5 in snowfall 2.2❄6 FebMarch: 3.35 in precipitation, 2.5 in snowfall 3.4❄3 MarApril: 4.80 in precipitation, 0.1 in snowfall 4.8 AprMay: 5.00 in precipitation 5.0 MayJune: 5.06 in precipitation 5.1 JunJuly: 4.31 in precipitation 4.3 JulAugust: 3.55 in precipitation 3.5 AugSeptember: 3.43 in precipitation 3.4 SepOctober: 3.22 in precipitation 3.2 OctNovember: 3.54 in precipitation, 0.5 in snowfall 3.5❄1 NovDecember: 3.16 in precipitation, 4.3 in snowfall 3.2❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Greenfield, IN (11 mi away); precipitation: Morristown 2 Se, IN (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

461046a
Arlington, IN · 2 mi
461616a
Morristown, IN · 3 mi
461156a
Carthage, IN · 7 mi
461466a
Homer, IN · 7 mi
461506a
Manilla, IN · 9 mi
461306a
Fountaintown, IN · 10 mi
461176a
Charlottesville, IN · 10 mi
461406a
Greenfield, IN · 12 mi

Indiana planting zones →

Questions about 46144

What planting zone is ZIP code 46144?

ZIP code 46144 (Gwynneville, IN) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Gwynneville, IN?

The median last spring frost (32 °F) near 46144 is April 19; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Greenfield station.

When is the first frost in Gwynneville, IN?

The median first fall frost near 46144 is October 22, giving a median frost-free growing season of 185 days.

When should I plant tomatoes in 46144?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 46144 get?

About 44.9 inches of precipitation a year and 20 inches of snowfall (NOAA 1991–2020 normals, Morristown 2 Se station).

How hot do summers get in Gwynneville, IN?

The average high peaks at 84 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 46144 have?

The USDA soil survey maps Crosby at the center of ZIP 46144: silt loam, somewhat poorly drained, pH about 5.9 (moderately acidic).

Did spring come early in Gwynneville, IN in 2026?

Spring leaf-out near 46144 came on Mar 10 in 2026, 16 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Gwynneville, IN?

Intermediate onions: the longest day near 46144 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.