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

Planting zone for 74728 — Broken Bow, OK

ZIP code 74728 (Broken Bow, McCurtain County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is April 1 and the first fall frost November 2.

Where ZIP 74728 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.

Zone8a10 to 15 °F

Coldest night−12.2 to −9.4 °C

Last frostApr 1

First frostNov 2

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 Broken Bow, 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 Broken Bow, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 1median — 50% chance of a later frost

Safe for tender plantsApril 17only 10% chance of frost after

First fall frostNovember 2median — 10% chance by Oct 20

Growing season220 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 13 and returns around November 14.

From the NOAA station Broken Bow 1 N, OK — 9 miles away, elevation 476 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 74728

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 18 – Mar 4

SpinachSow outdoors · Feb 18 – Mar 11

Broccoli, cabbageStart indoors · Jan 21 – Feb 4

Broccoli, cabbageTransplant · Mar 11 – Mar 25

Onion setsPlant outdoors · Mar 4 – Mar 18

PotatoesPlant outdoors · Mar 11 – Mar 25

LettuceSow outdoors · Mar 4 – Mar 18

Carrots, beetsSow outdoors · Mar 11 – Mar 25

TomatoesStart indoors · Feb 4 – Feb 18

TomatoesTransplant · Apr 8 – Apr 22

Peppers, eggplantStart indoors · Jan 21 – Feb 4

Peppers, eggplantTransplant · Apr 15 – Apr 29

BeansSow outdoors · Apr 8 – Apr 22

Sweet cornSow outdoors · Apr 8 – Apr 22

Cucumbers, squashSow outdoors · Apr 8 – Apr 22

Fall lettuce, spinachSow outdoors · Sep 7 – Sep 21

GarlicPlant cloves · Oct 19 – Nov 23

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 1) and first fall frost (Nov 2) 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 74728 came on Feb 11 — about the same time as the 1991–2020 average (Feb 13).

average
Feb 132026
Feb 11

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 Oklahoma

525 plants native to the lower 48 states, recorded in Oklahoma, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. 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 Broken Bow, OK.

Soil in Broken Bow, OK

The soil mapped at the center of ZIP 74728 is Clebit — very gravelly very fine sandy loam, well drained.

TextureVery gravelly very fine sandy loamdrains and warms fast; dries out and needs more feeding

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Clebit-Carnasaw-Stapp association, 12 to 20 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 74728; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Broken Bow, OK

Summer high93 °Faverage high, July

Winter low28 °Faverage low, January

Hot days81days a year at 90 °F or more

Freezing nights66nights a year at 32 °F or less

Growing degree days5,211base 50 °F — the season’s usable heat

Longest day14 h 26 mindaylight on June 21

Shortest day9 h 52 mindaylight on December 21

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

Precipitation51.6 inper year, rain and melted snow

Snowfall4 inper year; 2 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: Broken Bow 1 N, OK (9 mi away); precipitation: Carter Twr, OK (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

747378a

Golden, OK · 10 mi

747668a

Wright City, OK · 10 mi

Millerton, OK · 16 mi

747348a

Eagletown, OK · 17 mi

747548a

Ringold, OK · 17 mi

Oklahoma planting zones →

Questions about 74728

What planting zone is ZIP code 74728?

ZIP code 74728 (Broken Bow, OK) 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 Broken Bow, OK?

The median last spring frost (32 °F) near 74728 is April 1; after April 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Broken Bow 1 N station.

When is the first frost in Broken Bow, OK?

The median first fall frost near 74728 is November 2, giving a median frost-free growing season of 220 days.

When should I plant tomatoes in 74728?

Start tomato seeds indoors around Feb 4 – Feb 18 and set transplants outside around Apr 8 – Apr 22, one to three weeks after the median last frost.

How much rain and snow does 74728 get?

About 51.6 inches of precipitation a year and 4 inches of snowfall (NOAA 1991–2020 normals, Carter Twr station).

How hot do summers get in Broken Bow, OK?

The average high peaks at 93 °F in July, with about 81 days a year at 90 °F or more.

What kind of soil does 74728 have?

The USDA soil survey maps Clebit at the center of ZIP 74728: very gravelly very fine sandy loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Broken Bow, OK in 2026?

Spring leaf-out near 74728 came on Feb 11 in 2026, about the same as the 1991–2020 average (Feb 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Broken Bow, OK?

Intermediate onions: the longest day near 74728 is 14 h 26 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 74728 change?

Yes. The 2012 USDA map put 74728 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.