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

Planting zone for 73004 — Amber, OK

ZIP code 73004 (Amber, Grady County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 3 and the first fall frost November 4.

Where ZIP 73004 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 3

First frostNov 4

2012 zone7a

Was 7a 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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Amber, 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 Amber, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 3median — 50% chance of a later frost

Safe for tender plantsApril 19only 10% chance of frost after

First fall frostNovember 4median — 10% chance by Oct 21

Growing season214 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 22 and returns around November 13.

From the NOAA station Blanchard 2 Ssw, OK — 8 miles away, elevation 1,276 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 73004

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 20 – Mar 6

SpinachSow outdoors · Feb 20 – Mar 13

Broccoli, cabbageStart indoors · Jan 23 – Feb 6

Broccoli, cabbageTransplant · Mar 13 – Mar 27

Onion setsPlant outdoors · Mar 6 – Mar 20

PotatoesPlant outdoors · Mar 13 – Mar 27

LettuceSow outdoors · Mar 6 – Mar 20

Carrots, beetsSow outdoors · Mar 13 – Mar 27

TomatoesStart indoors · Feb 6 – Feb 20

TomatoesTransplant · Apr 10 – Apr 24

Peppers, eggplantStart indoors · Jan 23 – Feb 6

Peppers, eggplantTransplant · Apr 17 – May 1

BeansSow outdoors · Apr 10 – Apr 24

Sweet cornSow outdoors · Apr 10 – Apr 24

Cucumbers, squashSow outdoors · Apr 10 – Apr 24

Fall lettuce, spinachSow outdoors · Sep 9 – Sep 23

GarlicPlant cloves · Oct 21 – Nov 25

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 3) and first fall frost (Nov 4) 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 73004 came on Feb 12 — 10 days earlier than the 1991–2020 average (Feb 22).

average
Feb 222026
Feb 12

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 Amber, OK.

Soil in Amber, OK

The soil mapped at the center of ZIP 73004 is Grant — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH7.0neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Grant silt loam, 3 to 5 percent slopes, eroded.

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 73004; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Amber, OK

Summer high95 °Faverage high, July

Winter low27 °Faverage low, January

Hot days77days a year at 90 °F or more

Freezing nights72nights a year at 32 °F or less

Growing degree days5,292base 50 °F — the season’s usable heat

Longest day14 h 32 mindaylight on June 21

Shortest day9 h 47 mindaylight on December 21

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

Precipitation32 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: Blanchard 2 Ssw, OK (8 mi away); precipitation: Amber, OK (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

Chickasha, OK · 11 mi

730187b

Chickasha, OK · 12 mi

730657b

Newcastle, OK · 12 mi

Oklahoma planting zones →

Questions about 73004

What planting zone is ZIP code 73004?

ZIP code 73004 (Amber, 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 Amber, OK?

The median last spring frost (32 °F) near 73004 is April 3; after April 19 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Blanchard 2 Ssw station.

When is the first frost in Amber, OK?

The median first fall frost near 73004 is November 4, giving a median frost-free growing season of 214 days.

When should I plant tomatoes in 73004?

Start tomato seeds indoors around Feb 6 – Feb 20 and set transplants outside around Apr 10 – Apr 24, one to three weeks after the median last frost.

How much rain and snow does 73004 get?

About 32 inches of precipitation a year and 2 inches of snowfall (NOAA 1991–2020 normals, Amber station).

How hot do summers get in Amber, OK?

The average high peaks at 95 °F in July, with about 77 days a year at 90 °F or more.

What kind of soil does 73004 have?

The USDA soil survey maps Grant at the center of ZIP 73004: silt loam, well drained, pH about 7.0 (neutral).

Did spring come early in Amber, OK in 2026?

Spring leaf-out near 73004 came on Feb 12 in 2026, 10 days earlier than the 1991–2020 average (Feb 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Amber, OK?

Intermediate onions: the longest day near 73004 is 14 h 32 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 73004 change?

Yes. The 2012 USDA map put 73004 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.