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

Planting zone for 37381 — Spring City, TN

ZIP code 37381 (Spring City, Rhea County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 11 and the first fall frost October 29.

Where ZIP 37381 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 frostApr 11

First frostOct 29

2012 zone7a

Was 7a 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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Spring 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 Spring City, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 11median — 50% chance of a later frost

Safe for tender plantsMay 1only 10% chance of frost after

First fall frostOctober 29median — 10% chance by Oct 16

Growing season200 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 7.

From the NOAA station Spring City, TN — within 1 mile, elevation 755 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 37381

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 28 – Mar 14

SpinachSow outdoors · Feb 28 – Mar 21

Broccoli, cabbageStart indoors · Jan 31 – Feb 14

Broccoli, cabbageTransplant · Mar 21 – Apr 4

Onion setsPlant outdoors · Mar 14 – Mar 28

PotatoesPlant outdoors · Mar 21 – Apr 4

LettuceSow outdoors · Mar 14 – Mar 28

Carrots, beetsSow outdoors · Mar 21 – Apr 4

TomatoesStart indoors · Feb 14 – Feb 28

TomatoesTransplant · Apr 18 – May 2

Peppers, eggplantStart indoors · Jan 31 – Feb 14

Peppers, eggplantTransplant · Apr 25 – May 9

BeansSow outdoors · Apr 18 – May 2

Sweet cornSow outdoors · Apr 18 – May 2

Cucumbers, squashSow outdoors · Apr 18 – May 2

Fall lettuce, spinachSow outdoors · Sep 3 – Sep 17

GarlicPlant cloves · Oct 15 – Nov 19

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 11) and first fall frost (Oct 29) 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 37381 came on Feb 21 — 6 days earlier than the 1991–2020 average (Feb 27).

average
Feb 272026
Feb 21

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 Spring City, TN.

Soil in Spring City, TN

The soil mapped at the center of ZIP 37381 is Townley — silt loam, well drained.

TextureSilt loama good balance for most vegetables

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

DrainageWell drainednatural drainage class

Organic matter1.25%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Townley-Sunlight complex, 12 to 25 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 37381; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Spring City, TN

Summer high87 °Faverage high, July

Winter low26 °Faverage low, January

Hot days28days a year at 90 °F or more

Freezing nights91nights a year at 32 °F or less

Growing degree days4,092base 50 °F — the season’s usable heat

Longest day14 h 35 mindaylight on June 21

Shortest day9 h 44 mindaylight on December 21

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

Precipitation59.4 inper year, rain and melted snow

Snowfall1 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Spring City, TN (within 1 mile); precipitation: Spring City, TN (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

373377a

Grandview, TN · 7 mi

373327b

Evensville, TN · 7 mi

Crossville, TN · 15 mi

378547a

Rockwood, TN · 17 mi

385727a

Crossville, TN · 18 mi

Tennessee planting zones →

Questions about 37381

What planting zone is ZIP code 37381?

ZIP code 37381 (Spring 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 Spring City, TN?

The median last spring frost (32 °F) near 37381 is April 11; after May 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Spring City station.

When is the first frost in Spring City, TN?

The median first fall frost near 37381 is October 29, giving a median frost-free growing season of 200 days.

When should I plant tomatoes in 37381?

Start tomato seeds indoors around Feb 14 – Feb 28 and set transplants outside around Apr 18 – May 2, one to three weeks after the median last frost.

How much rain and snow does 37381 get?

About 59.4 inches of precipitation a year and 1 inches of snowfall (NOAA 1991–2020 normals, Spring City station).

How hot do summers get in Spring City, TN?

The average high peaks at 87 °F in July, with about 28 days a year at 90 °F or more.

What kind of soil does 37381 have?

The USDA soil survey maps Townley at the center of ZIP 37381: silt loam, well drained, pH about 5.3 (strongly acidic).

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

Spring leaf-out near 37381 came on Feb 21 in 2026, 6 days earlier than the 1991–2020 average (Feb 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Spring City, TN?

Intermediate onions: the longest day near 37381 is 14 h 35 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 37381 change?

Yes. The 2012 USDA map put 37381 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.