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

Planting zone for 73071 — Norman, OK

ZIP code 73071 (Norman, Cleveland County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is March 31 and the first fall frost November 5.

Where ZIP 73071 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 frostMar 31

First frostNov 5

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 Norman, 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 Norman, 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 17only 10% chance of frost after

First fall frostNovember 5median — 10% chance by Oct 21

Growing season219 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 16 and returns around November 14.

From the NOAA station Norman 2nw Mesonet, OK — 3 miles away, elevation 1,181 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 73071

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 10 – Sep 24

GarlicPlant cloves · Oct 22 – Nov 26

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 31) and first fall frost (Nov 5) 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 73071 came on Feb 12 — 9 days earlier than the 1991–2020 average (Feb 21).

average
Feb 212026
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 Norman, OK.

Soil in Norman, OK

The soil mapped at the center of ZIP 73071 is Renfrow — 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 groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Renfrow-Urban land-Huska complex, 1 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 73071; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Norman, OK

Summer high93 °Faverage high, July

Winter low29 °Faverage low, January

Hot days76days a year at 90 °F or more

Freezing nights72nights a year at 32 °F or less

Growing degree days5,241base 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

Precipitation37.4 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: Norman 2nw Mesonet, OK (3 mi away); precipitation: Norman 1.9 Ne, OK (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

Oklahoma City, OK · 8 mi

731657b

Oklahoma City, OK · 9 mi

730687b

Noble, OK · 10 mi

All 6 ZIP codes in Norman → · Oklahoma planting zones →

Questions about 73071

What planting zone is ZIP code 73071?

ZIP code 73071 (Norman, 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 Norman, OK?

The median last spring frost (32 °F) near 73071 is March 31; after April 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Norman 2nw Mesonet station.

When is the first frost in Norman, OK?

The median first fall frost near 73071 is November 5, giving a median frost-free growing season of 219 days.

When should I plant tomatoes in 73071?

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 73071 get?

About 37.4 inches of precipitation a year (NOAA 1991–2020 normals, Norman 1.9 Ne station).

How hot do summers get in Norman, OK?

The average high peaks at 93 °F in July, with about 76 days a year at 90 °F or more.

What kind of soil does 73071 have?

The USDA soil survey maps Renfrow at the center of ZIP 73071: silt loam, well drained, pH about 7.0 (neutral).

Did spring come early in Norman, OK in 2026?

Spring leaf-out near 73071 came on Feb 12 in 2026, 9 days earlier than the 1991–2020 average (Feb 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Norman, OK?

Intermediate onions: the longest day near 73071 is 14 h 32 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 73071 change?

Yes. The 2012 USDA map put 73071 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.