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

Planting zone for 73542 — Frederick, OK

ZIP code 73542 (Frederick, Tillman County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 26 and the first fall frost November 10.

Where ZIP 73542 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 26

First frostNov 10

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 Frederick, 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 Frederick, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 26median — 50% chance of a later frost

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

First fall frostNovember 10median — 10% chance by Oct 26

Growing season229 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 11 and returns around November 21.

From the NOAA station Altus AFB, OK — 3 miles away, elevation 1,266 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 73542

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 12 – Feb 26

SpinachSow outdoors · Feb 12 – Mar 5

Broccoli, cabbageStart indoors · Jan 15 – Jan 29

Broccoli, cabbageTransplant · Mar 5 – Mar 19

Onion setsPlant outdoors · Feb 26 – Mar 12

PotatoesPlant outdoors · Mar 5 – Mar 19

LettuceSow outdoors · Feb 26 – Mar 12

Carrots, beetsSow outdoors · Mar 5 – Mar 19

TomatoesStart indoors · Jan 29 – Feb 12

TomatoesTransplant · Apr 2 – Apr 16

Peppers, eggplantStart indoors · Jan 15 – Jan 29

Peppers, eggplantTransplant · Apr 9 – Apr 23

BeansSow outdoors · Apr 2 – Apr 16

Sweet cornSow outdoors · Apr 2 – Apr 16

Cucumbers, squashSow outdoors · Apr 2 – Apr 16

Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29

GarlicPlant cloves · Oct 27 – Dec 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 26) and first fall frost (Nov 10) 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 73542 came on Feb 10 — 6 days earlier than the 1991–2020 average (Feb 16).

average
Feb 162026
Feb 10

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 Frederick, OK.

Soil in Frederick, OK

The soil mapped at the center of ZIP 73542 is Tillman — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up

pH7.5slightly alkaline; 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: Tillman and Foard soils, 1 to 3 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 73542; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Frederick, OK

Summer high97 °Faverage high, July

Winter low30 °Faverage low, January

Hot days109days a year at 90 °F or more

Freezing nights64nights a year at 32 °F or less

Growing degree days5,877base 50 °F — the season’s usable heat

Longest day14 h 27 mindaylight on June 21

Shortest day9 h 51 mindaylight on December 21

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

Precipitation26.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Altus AFB, OK (3 mi away); precipitation: Frederick 6.0 Ssw, OK (9 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.

Chattanooga, OK · 16 mi

735468a

Grandfield, OK · 17 mi

Oklahoma planting zones →

Questions about 73542

What planting zone is ZIP code 73542?

ZIP code 73542 (Frederick, 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 Frederick, OK?

The median last spring frost (32 °F) near 73542 is March 26; after April 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Altus AFB station.

When is the first frost in Frederick, OK?

The median first fall frost near 73542 is November 10, giving a median frost-free growing season of 229 days.

When should I plant tomatoes in 73542?

Start tomato seeds indoors around Jan 29 – Feb 12 and set transplants outside around Apr 2 – Apr 16, one to three weeks after the median last frost.

How much rain and snow does 73542 get?

About 26.5 inches of precipitation a year (NOAA 1991–2020 normals, Frederick 6.0 Ssw station).

How hot do summers get in Frederick, OK?

The average high peaks at 97 °F in July, with about 109 days a year at 90 °F or more.

What kind of soil does 73542 have?

The USDA soil survey maps Tillman at the center of ZIP 73542: silty clay loam, well drained, pH about 7.5 (slightly alkaline).

Did spring come early in Frederick, OK in 2026?

Spring leaf-out near 73542 came on Feb 10 in 2026, 6 days earlier than the 1991–2020 average (Feb 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Frederick, OK?

Intermediate onions: the longest day near 73542 is 14 h 27 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 73542 change?

Yes. The 2012 USDA map put 73542 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.