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

Planting zone for 37401 — Chattanooga, TN

ZIP code 37401 (Chattanooga, Hamilton County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 31 and the first fall frost November 6.

Where ZIP 37401 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.

Zone8a10 to 15 °F
Coldest night−12.2 to −9.4 °C
Last frostMar 31
First frostNov 6
2012 zone7b

Was 7b 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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Chattanooga, 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 Chattanooga, TN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 31median — 50% chance of a later frost
Safe for tender plantsApril 18only 10% chance of frost after
First fall frostNovember 6median — 10% chance by Oct 24
Growing season219 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 21 and returns around November 17.

From the NOAA station Lookout Mtn-Point Park, TN — 3 miles away, elevation 2,110 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 37401

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 17 – Mar 3
SpinachSow outdoors · Feb 17 – Mar 10
Broccoli, cabbageStart indoors · Jan 20 – Feb 3
Broccoli, cabbageTransplant · Mar 10 – Mar 24
Onion setsPlant outdoors · Mar 3 – Mar 17
PotatoesPlant outdoors · Mar 10 – Mar 24
LettuceSow outdoors · Mar 3 – Mar 17
Carrots, beetsSow outdoors · Mar 10 – Mar 24
TomatoesStart indoors · Feb 3 – Feb 17
TomatoesTransplant · Apr 7 – Apr 21
Peppers, eggplantStart indoors · Jan 20 – Feb 3
Peppers, eggplantTransplant · Apr 14 – Apr 28
BeansSow outdoors · Apr 7 – Apr 21
Sweet cornSow outdoors · Apr 7 – Apr 21
Cucumbers, squashSow outdoors · Apr 7 – Apr 21
Fall lettuce, spinachSow outdoors · Sep 11 – Sep 25
GarlicPlant cloves · Oct 23 – Nov 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 31) and first fall frost (Nov 6) 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 37401 came on Feb 20 — 3 days later than the 1991–2020 average (Feb 17).

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 8a in Tennessee

575 plants native to the lower 48 states, recorded in Tennessee, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. Each links to its USDA PLANTS profile.

Trees 83

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 118

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 beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 186

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °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 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °F

Grasses 161

American cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °Fbig bluestem6 ft · blooms summer · high shade tolerance · to −46 °Fbluejoint5 ft · blooms late spring · high shade tolerance · to −33 °F

Vines 14

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fcupseed30 ft · blooms late spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium 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 Chattanooga, TN.

Soil in Chattanooga, TN

The center of ZIP 37401 is mapped as Urban land: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 37401; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Chattanooga, TN

Summer high84 °Faverage high, July
Winter low29 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights69nights a year at 32 °F or less
Growing degree days4,113base 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
Precipitation58.6 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 46 °F, low 29 °F 46°29° JanFebruary: average high 49 °F, low 31 °F 49°31° FebMarch: average high 58 °F, low 39 °F 58°39° MarApril: average high 68 °F, low 47 °F 68°47° AprMay: average high 74 °F, low 57 °F 74°57° MayJune: average high 81 °F, low 65 °F 81°65° JunJuly: average high 84 °F, low 67 °F 84°67° JulAugust: average high 82 °F, low 67 °F 82°67° AugSeptember: average high 78 °F, low 61 °F 78°61° SepOctober: average high 67 °F, low 51 °F 67°51° OctNovember: average high 57 °F, low 40 °F 57°40° NovDecember: average high 49 °F, low 32 °F 49°32° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 5.53 in precipitation 5.5 JanFebruary: 5.99 in precipitation 6.0 FebMarch: 5.59 in precipitation 5.6 MarApril: 5.52 in precipitation 5.5 AprMay: 4.31 in precipitation 4.3 MayJune: 4.21 in precipitation 4.2 JunJuly: 4.78 in precipitation 4.8 JulAugust: 3.98 in precipitation 4.0 AugSeptember: 4.92 in precipitation 4.9 SepOctober: 3.78 in precipitation 3.8 OctNovember: 4.62 in precipitation 4.6 NovDecember: 5.37 in precipitation 5.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Lookout Mtn-Point Park, TN (3 mi away); precipitation: Lookout Mtn-Point Park, TN (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8a.

374148a
Chattanooga, TN · <1 mi
374228a
Chattanooga, TN · <1 mi
374248a
Chattanooga, TN · <1 mi
374028a
Chattanooga, TN · <1 mi
374038a
Chattanooga, TN · <1 mi
374088a
Chattanooga, TN · 1 mi
374048a
Chattanooga, TN · 2 mi
374098a
Chattanooga, TN · 3 mi

All 19 ZIP codes in Chattanooga → · Tennessee planting zones →

Questions about 37401

What planting zone is ZIP code 37401?

ZIP code 37401 (Chattanooga, TN) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Chattanooga, TN?

The median last spring frost (32 °F) near 37401 is March 31; after April 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lookout Mtn-Point Park station.

When is the first frost in Chattanooga, TN?

The median first fall frost near 37401 is November 6, giving a median frost-free growing season of 219 days.

When should I plant tomatoes in 37401?

Start tomato seeds indoors around Feb 3 – Feb 17 and set transplants outside around Apr 7 – Apr 21, one to three weeks after the median last frost.

How much rain and snow does 37401 get?

About 58.6 inches of precipitation a year (NOAA 1991–2020 normals, Lookout Mtn-Point Park station).

How hot do summers get in Chattanooga, TN?

The average high peaks at 84 °F in July, with about 7 days a year at 90 °F or more.

Did spring come early in Chattanooga, TN in 2026?

Spring leaf-out near 37401 came on Feb 20 in 2026, 3 days later than the 1991–2020 average (Feb 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Chattanooga, TN?

Intermediate onions: the longest day near 37401 is 14 h 31 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 37401 change?

Yes. The 2012 USDA map put 37401 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.