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

Planting zone for 37059 — Dowelltown, TN

ZIP code 37059 (Dowelltown, DeKalb County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 18 and the first fall frost October 22.

Where ZIP 37059 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 18
First frostOct 22
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 Dowelltown, 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 Dowelltown, TN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 2only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 10
Growing season187 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 4 and returns around November 1.

From the NOAA station Smithville 2 Se, TN — 7 miles away, elevation 889 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 37059

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 22) 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 37059 came on Feb 21 — 5 days earlier than the 1991–2020 average (Feb 26).

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).

Soil in Dowelltown, TN

The soil mapped at the center of ZIP 37059 is Mimosa — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH5.6moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Mimosa-Rock outcrop complex, 20 to 40 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 37059; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dowelltown, TN

Summer high88 °Faverage high, July
Winter low26 °Faverage low, January
Hot days27days a year at 90 °F or more
Freezing nights102nights a year at 32 °F or less
Growing degree days4,066base 50 °F — the season’s usable heat
Longest day14 h 36 mindaylight on June 21
Shortest day9 h 43 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation60.8 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 47 °F, low 26 °F 47°26° JanFebruary: average high 52 °F, low 28 °F 52°28° FebMarch: average high 60 °F, low 35 °F 60°35° MarApril: average high 70 °F, low 42 °F 70°42° AprMay: average high 78 °F, low 53 °F 78°53° MayJune: average high 85 °F, low 61 °F 85°61° JunJuly: average high 88 °F, low 66 °F 88°66° JulAugust: average high 87 °F, low 64 °F 87°64° AugSeptember: average high 82 °F, low 56 °F 82°56° SepOctober: average high 72 °F, low 43 °F 72°43° OctNovember: average high 60 °F, low 33 °F 60°33° NovDecember: average high 51 °F, low 28 °F 51°28° Dec

Precipitation by month inches

0″2″4″6″January: 5.14 in precipitation 5.1 JanFebruary: 5.11 in precipitation 5.1 FebMarch: 5.58 in precipitation 5.6 MarApril: 5.01 in precipitation 5.0 AprMay: 5.40 in precipitation 5.4 MayJune: 5.64 in precipitation 5.6 JunJuly: 6.08 in precipitation 6.1 JulAugust: 4.17 in precipitation 4.2 AugSeptember: 4.34 in precipitation 4.3 SepOctober: 3.51 in precipitation 3.5 OctNovember: 4.53 in precipitation 4.5 NovDecember: 6.33 in precipitation 6.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Smithville 2 Se, TN (7 mi away); precipitation: Smithville 4.9 Wsw, TN (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

370957b
Liberty, TN · 4 mi
371667b
Smithville, TN · 8 mi
370127b
Alexandria, TN · 8 mi
385697b
Lancaster, TN · 10 mi
385677b
Hickman, TN · 10 mi
385827b
Silver Point, TN · 11 mi
370167b
Auburntown, TN · 12 mi
385477b
Brush Creek, TN · 13 mi

Tennessee planting zones →

Questions about 37059

What planting zone is ZIP code 37059?

ZIP code 37059 (Dowelltown, 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 Dowelltown, TN?

The median last spring frost (32 °F) near 37059 is April 18; after May 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Smithville 2 Se station.

When is the first frost in Dowelltown, TN?

The median first fall frost near 37059 is October 22, giving a median frost-free growing season of 187 days.

When should I plant tomatoes in 37059?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 37059 get?

About 60.8 inches of precipitation a year (NOAA 1991–2020 normals, Smithville 4.9 Wsw station).

How hot do summers get in Dowelltown, TN?

The average high peaks at 88 °F in July, with about 27 days a year at 90 °F or more.

What kind of soil does 37059 have?

The USDA soil survey maps Mimosa at the center of ZIP 37059: silt loam, well drained, pH about 5.6 (moderately acidic).

Did spring come early in Dowelltown, TN in 2026?

Spring leaf-out near 37059 came on Feb 21 in 2026, 5 days earlier than the 1991–2020 average (Feb 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dowelltown, TN?

Intermediate onions: the longest day near 37059 is 14 h 36 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 37059 change?

Yes. The 2012 USDA map put 37059 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.