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

Planting zone for 74957 — Smithville, OK

ZIP code 74957 (Smithville, McCurtain County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 9 and the first fall frost October 29.

Where ZIP 74957 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 9

First frostOct 29

2012 zone7b

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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Smithville, 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 Smithville, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 9median — 50% chance of a later frost

Safe for tender plantsApril 24only 10% chance of frost after

First fall frostOctober 29median — 10% chance by Oct 14

Growing season201 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 28 and returns around November 5.

From the NOAA station Smithville, OK — 4 miles away, elevation 824 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 74957

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 26 – Mar 12

SpinachSow outdoors · Feb 26 – Mar 19

Broccoli, cabbageStart indoors · Jan 29 – Feb 12

Broccoli, cabbageTransplant · Mar 19 – Apr 2

Onion setsPlant outdoors · Mar 12 – Mar 26

PotatoesPlant outdoors · Mar 19 – Apr 2

LettuceSow outdoors · Mar 12 – Mar 26

Carrots, beetsSow outdoors · Mar 19 – Apr 2

TomatoesStart indoors · Feb 12 – Feb 26

TomatoesTransplant · Apr 16 – Apr 30

Peppers, eggplantStart indoors · Jan 29 – Feb 12

Peppers, eggplantTransplant · Apr 23 – May 7

BeansSow outdoors · Apr 16 – Apr 30

Sweet cornSow outdoors · Apr 16 – Apr 30

Cucumbers, squashSow outdoors · Apr 16 – Apr 30

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 9) 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 74957 came on Feb 13 — 8 days earlier than the 1991–2020 average (Feb 21).

average
Feb 212026
Feb 13

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 Oklahoma

518 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 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 Smithville, OK.

Soil in Smithville, OK

The soil mapped at the center of ZIP 74957 is Sherless — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

pH5.9moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Sherless-Bengal complex, 3 to 15 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 74957; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Smithville, OK

Summer high91 °Faverage high, July

Winter low28 °Faverage low, January

Hot days48days a year at 90 °F or more

Freezing nights88nights a year at 32 °F or less

Growing degree days4,591base 50 °F — the season’s usable heat

Longest day14 h 28 mindaylight on June 21

Shortest day9 h 50 mindaylight on December 21

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

Precipitation57.5 inper year, rain and melted snow

Snowfall2 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: Smithville, OK (4 mi away); precipitation: Cove, AR (15 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.

Oklahoma planting zones →

Questions about 74957

What planting zone is ZIP code 74957?

ZIP code 74957 (Smithville, OK) 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 Smithville, OK?

The median last spring frost (32 °F) near 74957 is April 9; after April 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Smithville station.

When is the first frost in Smithville, OK?

The median first fall frost near 74957 is October 29, giving a median frost-free growing season of 201 days.

When should I plant tomatoes in 74957?

Start tomato seeds indoors around Feb 12 – Feb 26 and set transplants outside around Apr 16 – Apr 30, one to three weeks after the median last frost.

How much rain and snow does 74957 get?

About 57.5 inches of precipitation a year and 2 inches of snowfall (NOAA 1991–2020 normals, Cove station).

How hot do summers get in Smithville, OK?

The average high peaks at 91 °F in July, with about 48 days a year at 90 °F or more.

What kind of soil does 74957 have?

The USDA soil survey maps Sherless at the center of ZIP 74957: fine sandy loam, well drained, pH about 5.9 (moderately acidic).

Did spring come early in Smithville, OK in 2026?

Spring leaf-out near 74957 came on Feb 13 in 2026, 8 days earlier than the 1991–2020 average (Feb 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Smithville, OK?

Intermediate onions: the longest day near 74957 is 14 h 28 min, so day-neutral types bulb best; long-day varieties may not bulb fully.