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

Planting zone for 46401 — Gary, IN

ZIP code 46401 (Gary, Lake County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 22 and the first fall frost October 27.

Where ZIP 46401 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 22
First frostOct 27
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 Gary, 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 Gary, IN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 22median — 50% chance of a later frost
Safe for tender plantsMay 8only 10% chance of frost after
First fall frostOctober 27median — 10% chance by Oct 15
Growing season188 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 8 and returns around November 7.

From the NOAA station Indiana Dunes Nl, IN — 12 miles away, elevation 679 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 46401

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 11 – Mar 25
SpinachSow outdoors · Mar 11 – Apr 1
Broccoli, cabbageStart indoors · Feb 11 – Feb 25
Broccoli, cabbageTransplant · Apr 1 – Apr 15
Onion setsPlant outdoors · Mar 25 – Apr 8
PotatoesPlant outdoors · Apr 1 – Apr 15
LettuceSow outdoors · Mar 25 – Apr 8
Carrots, beetsSow outdoors · Apr 1 – Apr 15
TomatoesStart indoors · Feb 25 – Mar 11
TomatoesTransplant · Apr 29 – May 13
Peppers, eggplantStart indoors · Feb 11 – Feb 25
Peppers, eggplantTransplant · May 6 – May 20
BeansSow outdoors · Apr 29 – May 13
Sweet cornSow outdoors · Apr 29 – May 13
Cucumbers, squashSow outdoors · Apr 29 – May 13
Fall lettuce, spinachSow outdoors · Sep 1 – Sep 15
GarlicPlant cloves · Oct 13 – Nov 17
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 22) and first fall frost (Oct 27) 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 46401 came on Mar 21 — 14 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 Gary, IN.

Soil in Gary, IN

The soil mapped at the center of ZIP 46401 is Oakville — fine sand, excessively drained.

TextureFine sanddrains and warms fast; dries out and needs more feeding
pH5.1strongly acidic; most vegetables like 6.0–7.0
DrainageExcessively drainednatural drainage class
Organic matter2%moderate
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Oakville-Adrian complex, 0 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 46401; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Gary, IN

Summer high82 °Faverage high, July
Winter low18 °Faverage low, January
Hot days11days a year at 90 °F or more
Freezing nights117nights a year at 32 °F or less
Growing degree days3,043base 50 °F — the season’s usable heat
Longest day15 h 12 mindaylight on June 21
Shortest day9 h 09 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation40.8 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 32 °F, low 18 °F 32°18° JanFebruary: average high 36 °F, low 21 °F 36°21° FebMarch: average high 46 °F, low 30 °F 46°30° MarApril: average high 57 °F, low 40 °F 57°40° AprMay: average high 68 °F, low 50 °F 68°50° MayJune: average high 78 °F, low 60 °F 78°60° JunJuly: average high 82 °F, low 64 °F 82°64° JulAugust: average high 80 °F, low 63 °F 80°63° AugSeptember: average high 74 °F, low 56 °F 74°56° SepOctober: average high 62 °F, low 45 °F 62°45° OctNovember: average high 49 °F, low 34 °F 49°34° NovDecember: average high 37 °F, low 24 °F 37°24° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.29 in precipitation 2.3 JanFebruary: 2.40 in precipitation 2.4 FebMarch: 2.72 in precipitation 2.7 MarApril: 4.08 in precipitation 4.1 AprMay: 4.33 in precipitation 4.3 MayJune: 4.53 in precipitation 4.5 JunJuly: 3.93 in precipitation 3.9 JulAugust: 4.01 in precipitation 4.0 AugSeptember: 3.81 in precipitation 3.8 SepOctober: 3.52 in precipitation 3.5 OctNovember: 2.92 in precipitation 2.9 NovDecember: 2.25 in precipitation 2.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Indiana Dunes Nl, IN (12 mi away); precipitation: Gary 4.8 Ene, IN (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

464076a
Gary, IN · 1 mi
464026a
Gary, IN · 2 mi
464046a
Gary, IN · 3 mi
464096a
Gary, IN · 3 mi
464056a
Lake Station, IN · 3 mi
464036a
Gary, IN · 3 mi
464086a
Gary, IN · 4 mi
464066a
Gary, IN · 5 mi

All 8 ZIP codes in Gary → · Indiana planting zones →

Questions about 46401

What planting zone is ZIP code 46401?

ZIP code 46401 (Gary, 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 Gary, IN?

The median last spring frost (32 °F) near 46401 is April 22; after May 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Indiana Dunes Nl station.

When is the first frost in Gary, IN?

The median first fall frost near 46401 is October 27, giving a median frost-free growing season of 188 days.

When should I plant tomatoes in 46401?

Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.

How much rain and snow does 46401 get?

About 40.8 inches of precipitation a year (NOAA 1991–2020 normals, Gary 4.8 Ene station).

How hot do summers get in Gary, IN?

The average high peaks at 82 °F in July, with about 11 days a year at 90 °F or more.

What kind of soil does 46401 have?

The USDA soil survey maps Oakville at the center of ZIP 46401: fine sand, excessively drained, pH about 5.1 (strongly acidic).

Did spring come early in Gary, IN in 2026?

Spring leaf-out near 46401 came on Mar 21 in 2026, 14 days earlier than the 1991–2020 average (Apr 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Gary, IN?

Long-day onions: the longest day near 46401 is 15 h 12 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 46401 change?

Yes. The 2012 USDA map put 46401 in zone 5b; the 2023 map puts it in zone 6a. The newer map uses 1991–2020 data and more weather stations.