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

Planting zone for 74368 — Twin Oaks, OK

ZIP code 74368 (Twin Oaks, Delaware County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is March 31 and the first fall frost November 2.

Where ZIP 74368 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostMar 31
First frostNov 2
2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Twin Oaks, 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 Twin Oaks, OK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 31median — 50% chance of a later frost
Safe for tender plantsApril 18only 10% chance of frost after
First fall frostNovember 2median — 10% chance by Oct 20
Growing season216 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 19 and returns around November 12.

From the NOAA station Kansas 2 Ne, OK — 4 miles away, elevation 1,191 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 74368

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 17 – Mar 3
SpinachSow outdoors · Feb 17 – Mar 10
Broccoli, cabbageStart indoors · Jan 20 – Feb 3
Broccoli, cabbageTransplant · Mar 10 – Mar 24
Onion setsPlant outdoors · Mar 3 – Mar 17
PotatoesPlant outdoors · Mar 10 – Mar 24
LettuceSow outdoors · Mar 3 – Mar 17
Carrots, beetsSow outdoors · Mar 10 – Mar 24
TomatoesStart indoors · Feb 3 – Feb 17
TomatoesTransplant · Apr 7 – Apr 21
Peppers, eggplantStart indoors · Jan 20 – Feb 3
Peppers, eggplantTransplant · Apr 14 – Apr 28
BeansSow outdoors · Apr 7 – Apr 21
Sweet cornSow outdoors · Apr 7 – Apr 21
Cucumbers, squashSow outdoors · Apr 7 – Apr 21
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 (Mar 31) 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 74368 came on Feb 15 — 10 days earlier than the 1991–2020 average (Feb 25).

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 Twin Oaks, OK

The soil mapped at the center of ZIP 74368 is Doniphan — gravelly silt loam, well drained.

TextureGravelly silt loama good balance for most vegetables
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Doniphan-Tonti complex, 3 to 5 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 74368; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Twin Oaks, OK

Summer high91 °Faverage high, July
Winter low28 °Faverage low, January
Hot days41days a year at 90 °F or more
Freezing nights70nights a year at 32 °F or less
Growing degree days4,968base 50 °F — the season’s usable heat
Longest day14 h 38 mindaylight on June 21
Shortest day9 h 41 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation49.5 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 49 °F, low 28 °F 49°28° JanFebruary: average high 55 °F, low 32 °F 55°32° FebMarch: average high 63 °F, low 41 °F 63°41° MarApril: average high 72 °F, low 49 °F 72°49° AprMay: average high 78 °F, low 57 °F 78°57° MayJune: average high 86 °F, low 66 °F 86°66° JunJuly: average high 91 °F, low 70 °F 91°70° JulAugust: average high 91 °F, low 69 °F 91°69° AugSeptember: average high 84 °F, low 61 °F 84°61° SepOctober: average high 73 °F, low 50 °F 73°50° OctNovember: average high 61 °F, low 40 °F 61°40° NovDecember: average high 52 °F, low 32 °F 52°32° Dec

Precipitation by month inches

0″2″4″6″January: 3.23 in precipitation 3.2 JanFebruary: 2.50 in precipitation 2.5 FebMarch: 4.11 in precipitation 4.1 MarApril: 4.92 in precipitation 4.9 AprMay: 6.22 in precipitation 6.2 MayJune: 5.04 in precipitation 5.0 JunJuly: 4.14 in precipitation 4.1 JulAugust: 3.76 in precipitation 3.8 AugSeptember: 4.47 in precipitation 4.5 SepOctober: 4.18 in precipitation 4.2 OctNovember: 3.88 in precipitation 3.9 NovDecember: 3.03 in precipitation 3.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Kansas 2 Ne, OK (4 mi away); precipitation: Upper Spavinaw Port, OK (10 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.

743597a
Oaks, OK · 3 mi
743477a
Kansas, OK · 3 mi
743647a
Rose, OK · 6 mi
743387a
Colcord, OK · 8 mi
749647a
Watts, OK · 12 mi
744447b
Moodys, OK · 13 mi
743657a
Salina, OK · 13 mi
744527b
Peggs, OK · 14 mi

Oklahoma planting zones →

Questions about 74368

What planting zone is ZIP code 74368?

ZIP code 74368 (Twin Oaks, OK) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Twin Oaks, OK?

The median last spring frost (32 °F) near 74368 is March 31; after April 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Kansas 2 Ne station.

When is the first frost in Twin Oaks, OK?

The median first fall frost near 74368 is November 2, giving a median frost-free growing season of 216 days.

When should I plant tomatoes in 74368?

Start tomato seeds indoors around Feb 3 – Feb 17 and set transplants outside around Apr 7 – Apr 21, one to three weeks after the median last frost.

How much rain and snow does 74368 get?

About 49.5 inches of precipitation a year (NOAA 1991–2020 normals, Upper Spavinaw Port station).

How hot do summers get in Twin Oaks, OK?

The average high peaks at 91 °F in July, with about 41 days a year at 90 °F or more.

What kind of soil does 74368 have?

The USDA soil survey maps Doniphan at the center of ZIP 74368: gravelly silt loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Twin Oaks, OK in 2026?

Spring leaf-out near 74368 came on Feb 15 in 2026, 10 days earlier than the 1991–2020 average (Feb 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Twin Oaks, OK?

Intermediate onions: the longest day near 74368 is 14 h 38 min, so day-neutral types bulb best; long-day varieties may not bulb fully.