US Grow Zones

Oklahoma City, Oklahoma: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USW00013967); U.S. Census Bureau — see methodology

Oklahoma City is in USDA plant hardiness zone 7b, where the average coldest winter night reaches 5 to 10°F (-15.0 to -12.2°C). The typical last spring frost is around Apr 10 and the first fall frost around Oct 29.

Hardiness zone7B5 to 10°F
Last spring frostApr 1030% chance of frost after
First fall frostOct 2930% chance of frost before
Growing season213 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)Apr 20Oct 21
Typical planning date (30% risk)Apr 10Oct 29
Median (50%)Apr 4Nov 2

How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.

Frost data comes from NOAA station OKLAHOMA CITY WILL ROGERS AP, OK (USW00013967), 7.3 mi (11.7 km) from the city center and 89 ft higher than the city center (+27 m). Record used for the 1991–2020 normals: 29 years.

Frost probability in spring and fall, Oklahoma City, OKChance of a 32°F frost in Oklahoma City, OK, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Mar 16 to 10% on Apr 20. Fall: the chance that the first frost has arrived rises from 10% on Oct 21 to 90% on Nov 17.0%50%100%Spring: later frostMar 1Mar 15Apr 1Apr 1530%: Apr 10Fall: frost arrivedOct 15Nov 1Nov 15Dec 130%: Oct 2932°F frost28°F hard freezeplanning date
Shaded areas show the chance of a 32°F frost: falling through spring, rising through fall. The dashed line is the 28°F hard-freeze curve. Data: NOAA 1991–2020 Normals, station USW00013967.
Frost-free growing season in Oklahoma City, OK1 in 10 risk: Apr 20 to Oct 21 (184 days); 3 in 10 risk: Apr 10 to Oct 29 (202 days); Median (50%): Apr 4 to Nov 2 (212 days); No 28°F freeze: Mar 21 to Nov 11 (235 days). In 9 of 10 years the 32°F-free season is at least 191 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk184 days3 in 10 risk202 daysMedian (50%)212 daysNo 28°F freeze235 days
Frost-free window at three risk levels, plus the window between 28°F hard freezes. Read about what the probabilities mean.

Why your yard may differ from the station: microclimates.

Hardiness zone across Oklahoma City

All 50 ZIP codes covering Oklahoma City are in zone 7b.

ZIP codes in Oklahoma City and their zones
ZIPZoneShare of city land
730997b12.9%
731657b6.3%
730647b6.2%
748577b5.5%
730497b5.4%
730137b3.3%
730207b3.3%
731707b3.3%
731507b3.1%
731597b2.3%
731737b2.2%
730547b2.1%
731297b2.1%
730847b2.0%
731317b2.0%
731277b1.9%
731797b1.9%
731357b1.8%
730127b1.6%
731147b1.6%
731117b1.4%
730787b1.3%
731127b1.3%
731207b1.3%
731427b1.3%
731077b1.2%
731087b1.2%
731287b1.2%
731417b1.2%
731627b1.2%
731697b1.2%
731197b1.1%
731217b1.1%
731327b1.1%
748517b1.1%
731097b0.9%
731497b0.9%
731177b0.8%
731187b0.8%
731057b0.7%
731167b0.7%
731347b0.7%
731397b0.7%
731067b0.5%
731517b0.5%
731047b0.3%
730977b0.2%
731037b0.2%
731457b0.2%
731027b0.1%

Vegetable planting calendar for Oklahoma City

Dates are counted from the 30%-risk frost dates above (last frost Apr 10, first frost Oct 29). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoFeb 13 – Feb 27Apr 17 – May 1——
PepperJan 30 – Feb 13Apr 24 – May 8——
LettuceFeb 27 – Mar 13Mar 27 – Apr 17Mar 13 – Apr 24Aug 20 – Sep 17
Green Beans——Apr 17 – May 22Aug 6 – Aug 20
Sweet Corn——Apr 17 – May 15—
Zucchini & Summer SquashMar 13 – Mar 20Apr 17 – May 1Apr 17 – May 8Aug 6 – Aug 20
CucumberMar 13 – Mar 20Apr 24 – May 1Apr 17 – May 8Aug 6 – Aug 20
Carrot——Mar 20 – Apr 24Aug 6 – Aug 20
OnionJan 16 – Jan 30Mar 13 – Mar 27——
Potato—Mar 13 – Apr 3——
BasilFeb 27 – Mar 13Apr 24 – May 8Apr 24 – May 15—
Spinach——Feb 27 – Mar 27Sep 3 – Oct 1
KaleFeb 13 – Feb 27Mar 13 – Apr 3Mar 13 – Apr 3Aug 20 – Sep 17
BroccoliFeb 13 – Feb 27Mar 27 – Apr 17—Aug 6 – Aug 20
Peas——Feb 27 – Mar 20Aug 20 – Sep 3
EggplantJan 30 – Feb 13Apr 24 – May 8——
CabbageFeb 13 – Feb 27Mar 13 – Mar 27—Aug 6 – Aug 20
Radish——Mar 6 – Apr 24Sep 17 – Oct 15
Strawberry—Mar 13 – Apr 3——
Beets——Mar 20 – May 1Aug 20 – Sep 3

Nearby cities in Oklahoma

More: all Oklahoma cities · other zone 7b cities: New York, NY, Philadelphia, PA, Nashville, TN, Washington, DC, Baltimore, MD, Albuquerque, NM, Tulsa, OK, Newark, NJ

Oklahoma City gardening questions

When is the last frost in Oklahoma City, OK?

Plan around Apr 10. At NOAA's Oklahoma City Will Rogers Airport, OK station, 7.3 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 4, and after Apr 20 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 21. The 90% and 10% dates are 35 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Oklahoma City, OK?

Start seeds indoors Feb 13 – Feb 27 and set transplants outside Apr 17 – May 1, once nights stay above 50°F and the soil is near 60°F. That leaves 202 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.

How long is the growing season in Oklahoma City?

About 213 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 191 days, and in 1 year in 10 it runs 235 days or more. In fall there is a 10% chance of frost by Oct 21 and a 30% chance by Oct 29. That ranks 3rd longest of 6 Oklahoma cities on this site.

When should I plant a fall garden in Oklahoma City?

Count back from the first fall frost (Oct 29): transplant broccoli Aug 6 – Aug 20; sow kale Aug 20 – Sep 17; sow lettuce Aug 20 – Sep 17; sow radishes Sep 17 – Oct 15. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 11. How the math works: succession and fall planting.

Did Oklahoma City's hardiness zone change on the 2023 map?

Yes. Most of Oklahoma City was zone 7a on the 2012 map and is zone 7b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.

How does Oklahoma City compare with Edmond, OK?

Both are in zone 7b. The typical last spring frost in Oklahoma City (Apr 10) comes about 8 days earlier than in Edmond, OK (Apr 18), 15 miles away, and the first fall frost is Oct 29 versus Oct 23. The two cities use different NOAA stations.