Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for 73439 — Kingston, OK

ZIP code 73439 (Kingston, Marshall County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 27 and the first fall frost November 8.

Where ZIP 73439 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 frostMar 27

First frostNov 8

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 Kingston, 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 Kingston, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 27median — 50% chance of a later frost

Safe for tender plantsApril 14only 10% chance of frost after

First fall frostNovember 8median — 10% chance by Oct 25

Growing season227 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 11 and returns around November 19.

From the NOAA station Madill, OK — 11 miles away, elevation 771 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 73439

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 13 – Feb 27

SpinachSow outdoors · Feb 13 – Mar 6

Broccoli, cabbageStart indoors · Jan 16 – Jan 30

Broccoli, cabbageTransplant · Mar 6 – Mar 20

Onion setsPlant outdoors · Feb 27 – Mar 13

PotatoesPlant outdoors · Mar 6 – Mar 20

LettuceSow outdoors · Feb 27 – Mar 13

Carrots, beetsSow outdoors · Mar 6 – Mar 20

TomatoesStart indoors · Jan 30 – Feb 13

TomatoesTransplant · Apr 3 – Apr 17

Peppers, eggplantStart indoors · Jan 16 – Jan 30

Peppers, eggplantTransplant · Apr 10 – Apr 24

BeansSow outdoors · Apr 3 – Apr 17

Sweet cornSow outdoors · Apr 3 – Apr 17

Cucumbers, squashSow outdoors · Apr 3 – Apr 17

Fall lettuce, spinachSow outdoors · Sep 13 – Sep 27

GarlicPlant cloves · Oct 25 – Nov 29

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 27) and first fall frost (Nov 8) 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 73439 came on Feb 9 — 3 days earlier than the 1991–2020 average (Feb 12).

average
Feb 122026
Feb 9

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 Kingston, OK.

Soil in Kingston, OK

The soil mapped at the center of ZIP 73439 is Swink — very cobbly clay loam, well drained.

TextureVery cobbly clay loamholds water and nutrients; slow to drain and warm up

pH7.9alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Swink very cobbly clay loam, 2 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 73439; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kingston, OK

Summer high95 °Faverage high, July

Winter low30 °Faverage low, January

Hot days87days a year at 90 °F or more

Freezing nights63nights a year at 32 °F or less

Growing degree days5,668base 50 °F — the season’s usable heat

Longest day14 h 25 mindaylight on June 21

Shortest day9 h 53 mindaylight on December 21

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

Precipitation41.6 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: Madill, OK (11 mi away); precipitation: Kingston 5 Sse, OK (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8a.

734408a

Lebanon, OK · 8 mi

750768a

Pottsboro, TX · 10 mi

762458a

Gordonville, TX · 10 mi

734468a

Madill, OK · 11 mi

747318a

Cartwright, OK · 11 mi

Oklahoma planting zones →

Questions about 73439

What planting zone is ZIP code 73439?

ZIP code 73439 (Kingston, 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 Kingston, OK?

The median last spring frost (32 °F) near 73439 is March 27; after April 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Madill station.

When is the first frost in Kingston, OK?

The median first fall frost near 73439 is November 8, giving a median frost-free growing season of 227 days.

When should I plant tomatoes in 73439?

Start tomato seeds indoors around Jan 30 – Feb 13 and set transplants outside around Apr 3 – Apr 17, one to three weeks after the median last frost.

How much rain and snow does 73439 get?

About 41.6 inches of precipitation a year and 2 inches of snowfall (NOAA 1991–2020 normals, Kingston 5 Sse station).

How hot do summers get in Kingston, OK?

The average high peaks at 95 °F in July, with about 87 days a year at 90 °F or more.

What kind of soil does 73439 have?

The USDA soil survey maps Swink at the center of ZIP 73439: very cobbly clay loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Kingston, OK in 2026?

Spring leaf-out near 73439 came on Feb 9 in 2026, 3 days earlier than the 1991–2020 average (Feb 12), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Kingston, OK?

Intermediate onions: the longest day near 73439 is 14 h 25 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 73439 change?

Yes. The 2012 USDA map put 73439 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.