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

Planting zone for 46581 — Warsaw, IN

ZIP code 46581 (Warsaw, Kosciusko County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 28 and the first fall frost October 18.

Where ZIP 46581 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.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 28
First frostOct 18
2012 zone5b

Was 5b 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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Warsaw, 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 Warsaw, IN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 28median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 18median — 10% chance by Oct 1
Growing season170 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 16 and returns around October 30.

From the NOAA station Warsaw, IN — 2 miles away, elevation 814 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 46581

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 17 – Mar 31
SpinachSow outdoors · Mar 17 – Apr 7
Broccoli, cabbageStart indoors · Feb 17 – Mar 3
Broccoli, cabbageTransplant · Apr 7 – Apr 21
Onion setsPlant outdoors · Mar 31 – Apr 14
PotatoesPlant outdoors · Apr 7 – Apr 21
LettuceSow outdoors · Mar 31 – Apr 14
Carrots, beetsSow outdoors · Apr 7 – Apr 21
TomatoesStart indoors · Mar 3 – Mar 17
TomatoesTransplant · May 5 – May 19
Peppers, eggplantStart indoors · Feb 17 – Mar 3
Peppers, eggplantTransplant · May 12 – May 26
BeansSow outdoors · May 5 – May 19
Sweet cornSow outdoors · May 5 – May 19
Cucumbers, squashSow outdoors · May 5 – May 19
Fall lettuce, spinachSow outdoors · Aug 23 – Sep 6
GarlicPlant cloves · Oct 4 – Nov 8
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 28) and first fall frost (Oct 18) 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 46581 came on Mar 16 — 19 days earlier than the 1991–2020 average (Apr 4).

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 Warsaw, IN.

Soil in Warsaw, IN

The soil mapped at the center of ZIP 46581 is Ormas — loamy sand, well drained.

TextureLoamy sanddrains and warms fast; dries out and needs more feeding
pH6.8neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Ormas loamy sand, 2 to 6 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 46581; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Warsaw, IN

Summer high84 °Faverage high, July
Winter low17 °Faverage low, January
Hot days12days a year at 90 °F or more
Freezing nights132nights a year at 32 °F or less
Growing degree days3,023base 50 °F — the season’s usable heat
Longest day15 h 09 mindaylight on June 21
Shortest day9 h 12 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation40.5 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 33 °F, low 17 °F 33°17° JanFebruary: average high 37 °F, low 19 °F 37°19° FebMarch: average high 48 °F, low 28 °F 48°28° MarApril: average high 61 °F, low 38 °F 61°38° AprMay: average high 72 °F, low 49 °F 72°49° MayJune: average high 81 °F, low 58 °F 81°58° JunJuly: average high 84 °F, low 62 °F 84°62° JulAugust: average high 82 °F, low 60 °F 82°60° AugSeptember: average high 76 °F, low 52 °F 76°52° SepOctober: average high 64 °F, low 42 °F 64°42° OctNovember: average high 50 °F, low 31 °F 50°31° NovDecember: average high 38 °F, low 22 °F 38°22° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.59 in precipitation 2.6 JanFebruary: 1.98 in precipitation 2.0 FebMarch: 2.16 in precipitation 2.2 MarApril: 4.05 in precipitation 4.0 AprMay: 4.89 in precipitation 4.9 MayJune: 4.72 in precipitation 4.7 JunJuly: 4.41 in precipitation 4.4 JulAugust: 4.52 in precipitation 4.5 AugSeptember: 2.90 in precipitation 2.9 SepOctober: 3.17 in precipitation 3.2 OctNovember: 2.71 in precipitation 2.7 NovDecember: 2.44 in precipitation 2.4 Dec

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

465806a
Warsaw, IN · 2 mi
465826a
Warsaw, IN · 3 mi
465906a
Winona Lake, IN · 3 mi
465026a
Atwood, IN · 6 mi
465386a
Leesburg, IN · 7 mi
465106a
Claypool, IN · 8 mi
465246a
Etna Green, IN · 9 mi
465626a
Pierceton, IN · 10 mi

All 3 ZIP codes in Warsaw → · Indiana planting zones →

Questions about 46581

What planting zone is ZIP code 46581?

ZIP code 46581 (Warsaw, 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 Warsaw, IN?

The median last spring frost (32 °F) near 46581 is April 28; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Warsaw station.

When is the first frost in Warsaw, IN?

The median first fall frost near 46581 is October 18, giving a median frost-free growing season of 170 days.

When should I plant tomatoes in 46581?

Start tomato seeds indoors around Mar 3 – Mar 17 and set transplants outside around May 5 – May 19, one to three weeks after the median last frost.

How much rain and snow does 46581 get?

About 40.5 inches of precipitation a year (NOAA 1991–2020 normals, Warsaw station).

How hot do summers get in Warsaw, IN?

The average high peaks at 84 °F in July, with about 12 days a year at 90 °F or more.

What kind of soil does 46581 have?

The USDA soil survey maps Ormas at the center of ZIP 46581: loamy sand, well drained, pH about 6.8 (neutral).

Did spring come early in Warsaw, IN in 2026?

Spring leaf-out near 46581 came on Mar 16 in 2026, 19 days earlier than the 1991–2020 average (Apr 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Warsaw, IN?

Long-day onions: the longest day near 46581 is 15 h 09 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 46581 change?

Yes. The 2012 USDA map put 46581 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.