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

Planting zone for 38463 — Iron City, TN

ZIP code 38463 (Iron City, Lawrence County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is March 29 and the first fall frost November 4.

Where ZIP 38463 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.

Zone7b5 to 10 °F

Coldest night−15 to −12.2 °C

Last frostMar 29

First frostNov 4

2012 zone7b

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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Iron City, TN…

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 Iron City, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 29median — 50% chance of a later frost

Safe for tender plantsApril 15only 10% chance of frost after

First fall frostNovember 4median — 10% chance by Oct 21

Growing season219 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 15 and returns around November 16.

From the NOAA station Lexington, AL — 17 miles away, elevation 761 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 38463

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 15 – Mar 1

SpinachSow outdoors · Feb 15 – Mar 8

Broccoli, cabbageStart indoors · Jan 18 – Feb 1

Broccoli, cabbageTransplant · Mar 8 – Mar 22

Onion setsPlant outdoors · Mar 1 – Mar 15

PotatoesPlant outdoors · Mar 8 – Mar 22

LettuceSow outdoors · Mar 1 – Mar 15

Carrots, beetsSow outdoors · Mar 8 – Mar 22

TomatoesStart indoors · Feb 1 – Feb 15

TomatoesTransplant · Apr 5 – Apr 19

Peppers, eggplantStart indoors · Jan 18 – Feb 1

Peppers, eggplantTransplant · Apr 12 – Apr 26

BeansSow outdoors · Apr 5 – Apr 19

Sweet cornSow outdoors · Apr 5 – Apr 19

Cucumbers, squashSow outdoors · Apr 5 – Apr 19

Fall lettuce, spinachSow outdoors · Sep 9 – Sep 23

GarlicPlant cloves · Oct 21 – Nov 25

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 29) and first fall frost (Nov 4) 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 38463 came on Feb 20 — about the same time as the 1991–2020 average (Feb 21).

average
Feb 212026
Feb 20

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 7b in Tennessee

566 plants native to the lower 48 states, recorded in Tennessee, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. 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 Iron City, TN.

Soil in Iron City, TN

The soil mapped at the center of ZIP 38463 is Lobelville — gravelly silt loam, moderately well drained.

TextureGravelly silt loama good balance for most vegetables

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter2%moderate

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Lobelville gravelly silt loam, occasionally flooded.

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 38463; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Iron City, TN

Summer high90 °Faverage high, July

Winter low31 °Faverage low, January

Hot days43days a year at 90 °F or more

Freezing nights70nights a year at 32 °F or less

Growing degree days5,031base 50 °F — the season’s usable heat

Longest day14 h 31 mindaylight on June 21

Shortest day9 h 48 mindaylight on December 21

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

Precipitation58.8 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: Lexington, AL (17 mi away); precipitation: Loretto 5.2 Ne, TN (16 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

384527b

Cypress Inn, TN · 8 mi

384867b

Westpoint, TN · 9 mi

384507b

Collinwood, TN · 9 mi

384817b

Saint Joseph, TN · 9 mi

356347b

Florence, AL · 10 mi

356177b

Cloverdale, AL · 12 mi

Tennessee planting zones →

Questions about 38463

What planting zone is ZIP code 38463?

ZIP code 38463 (Iron City, TN) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Iron City, TN?

The median last spring frost (32 °F) near 38463 is March 29; after April 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lexington station.

When is the first frost in Iron City, TN?

The median first fall frost near 38463 is November 4, giving a median frost-free growing season of 219 days.

When should I plant tomatoes in 38463?

Start tomato seeds indoors around Feb 1 – Feb 15 and set transplants outside around Apr 5 – Apr 19, one to three weeks after the median last frost.

How much rain and snow does 38463 get?

About 58.8 inches of precipitation a year (NOAA 1991–2020 normals, Loretto 5.2 Ne station).

How hot do summers get in Iron City, TN?

The average high peaks at 90 °F in July, with about 43 days a year at 90 °F or more.

What kind of soil does 38463 have?

The USDA soil survey maps Lobelville at the center of ZIP 38463: gravelly silt loam, moderately well drained, pH about 5.3 (strongly acidic).

Did spring come early in Iron City, TN in 2026?

Spring leaf-out near 38463 came on Feb 20 in 2026, about the same as the 1991–2020 average (Feb 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Iron City, TN?

Intermediate onions: the longest day near 38463 is 14 h 31 min, so day-neutral types bulb best; long-day varieties may not bulb fully.