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

Planting zone for 73939 — Goodwell, OK

ZIP code 73939 (Goodwell, Texas County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 24 and the first fall frost October 19.

Where ZIP 73939 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostApr 24

First frostOct 19

2012 zone6b

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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Goodwell, OK…

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 Goodwell, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 24median — 50% chance of a later frost

Safe for tender plantsMay 6only 10% chance of frost after

First fall frostOctober 19median — 10% chance by Oct 6

Growing season178 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 13 and returns around October 29.

From the NOAA station Goodwell Rsch Stn, OK — 16 miles away, elevation 3,278 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 73939

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 13 – Mar 27

SpinachSow outdoors · Mar 13 – Apr 3

Broccoli, cabbageStart indoors · Feb 13 – Feb 27

Broccoli, cabbageTransplant · Apr 3 – Apr 17

Onion setsPlant outdoors · Mar 27 – Apr 10

PotatoesPlant outdoors · Apr 3 – Apr 17

LettuceSow outdoors · Mar 27 – Apr 10

Carrots, beetsSow outdoors · Apr 3 – Apr 17

TomatoesStart indoors · Feb 27 – Mar 13

TomatoesTransplant · May 1 – May 15

Peppers, eggplantStart indoors · Feb 13 – Feb 27

Peppers, eggplantTransplant · May 8 – May 22

BeansSow outdoors · May 1 – May 15

Sweet cornSow outdoors · May 1 – May 15

Cucumbers, squashSow outdoors · May 1 – May 15

Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7

GarlicPlant cloves · Oct 5 – Nov 9

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 24) and first fall frost (Oct 19) 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 73939 came on Feb 17 — 18 days earlier than the 1991–2020 average (Mar 7).

average
Mar 72026
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 6b in Oklahoma

489 plants native to the lower 48 states, recorded in Oklahoma, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 Goodwell, OK.

Soil in Goodwell, OK

The soil mapped at the center of ZIP 73939 is Sherm — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up

pH7.2neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Sherm clay loam, 0 to 1 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 73939; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Goodwell, OK

Summer high93 °Faverage high, July

Winter low20 °Faverage low, January

Hot days82days a year at 90 °F or more

Freezing nights132nights a year at 32 °F or less

Growing degree days4,051base 50 °F — the season’s usable heat

Longest day14 h 41 mindaylight on June 21

Shortest day9 h 38 mindaylight on December 21

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

Precipitation16.7 inper year, rain and melted snow

Snowfall3 inper year; 1 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Goodwell Rsch Stn, OK (16 mi away); precipitation: Goodwell Rsch Stn, OK (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.

Richfield, KS · 31 mi

790516b

Kerrick, TX · 33 mi

Oklahoma planting zones →

Questions about 73939

What planting zone is ZIP code 73939?

ZIP code 73939 (Goodwell, OK) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Goodwell, OK?

The median last spring frost (32 °F) near 73939 is April 24; after May 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Goodwell Rsch Stn station.

When is the first frost in Goodwell, OK?

The median first fall frost near 73939 is October 19, giving a median frost-free growing season of 178 days.

When should I plant tomatoes in 73939?

Start tomato seeds indoors around Feb 27 – Mar 13 and set transplants outside around May 1 – May 15, one to three weeks after the median last frost.

How much rain and snow does 73939 get?

About 16.7 inches of precipitation a year and 3 inches of snowfall (NOAA 1991–2020 normals, Goodwell Rsch Stn station).

How hot do summers get in Goodwell, OK?

The average high peaks at 93 °F in July, with about 82 days a year at 90 °F or more.

What kind of soil does 73939 have?

The USDA soil survey maps Sherm at the center of ZIP 73939: clay loam, well drained, pH about 7.2 (neutral).

Did spring come early in Goodwell, OK in 2026?

Spring leaf-out near 73939 came on Feb 17 in 2026, 18 days earlier than the 1991–2020 average (Mar 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Goodwell, OK?

Intermediate onions: the longest day near 73939 is 14 h 41 min, so day-neutral types bulb best; long-day varieties may not bulb fully.