Oklahoma City, Oklahoma Frost Dates, Growing Season & Hardiness Zone

When is the last frost in Oklahoma City?

In half of years, the last 32°F night has passed by Apr 4. In 1 year out of 10, one still comes after Apr 20. The last 36°F night (frost possible on plants) typically comes later, around Apr 15, and the last 28°F hard freeze earlier, around Mar 21.

Frost risk in Oklahoma City drags on well past the typical date. The safer 1-in-10 date (Apr 20) is 16 days later than the typical Apr 4, so protect tender plants set out early on cold nights.

Cold nights don't end with the last freeze. The typical last 36°F night (frost possible on plants in low spots) comes around Apr 15, 11 days after the typical last 32°F night. On clear, calm nights, frost can form on leaves while the thermometer still reads above freezing.

Our station has the latest typical last frost of the 5 eligible stations near Oklahoma City. For most of the area, these dates are on the cautious side.

Is it too early to plant in Oklahoma City?

Before Apr 4 the odds of another 32°F night are better than even; after Apr 20 they are about 1 in 10 or less.

Today's risk is computed in your browser from the same NOAA probability table, shown as the range between the two nearest NOAA probability levels.

When is the first frost in Oklahoma City?

By Nov 2, half of years have had their first 32°F night. In 1 year out of 10, it comes as early as Oct 21. In a typical year, look for the first 36°F night (frost possible on plants) around Oct 26 and the first 28°F hard freeze around Nov 11.

Fall plantings are timed backward from first frost: Nov 2 typically, or Oct 21 if you want a cushion. See the planting calendar for each crop's date.

How long is Oklahoma City's growing season?

A typical year in Oklahoma City has 213 days between the last spring and first fall 32°F nights. In about 1 year in 10, there are fewer than 191 days.

Most warm-season vegetables have time to finish if you plant on schedule. For long-season crops, transplants do best.

The station averages 4,971 growing degree days (base 50°F) a year. That number measures how much heat crops have to grow on.

How does Oklahoma City's season compare?

Nationwide, across the 56 cities with frost dates on this site, the typical frost-free season here outlasts the one in 29 of them and falls short of the one in 25.

Growing degree days (base 50°F)

Annual normal: 4,971 GDD (NOAA flag S, 27 years). Running total by the end of each month (sum of NOAA daily GDD normals, so the year-end total can differ slightly from the annual normal):

What growing zone is Oklahoma City? (USDA 2023)

Oklahoma City is in USDA zone 7b on the 2023 map, which means an average coldest winter night of 5 to 10°F. Most of the city was 7a on the 2012 map, and 60 of 60 city ZIPs found in both tables moved up half a zone.

Zones: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed 2026-10-08. Shown as published in the ZIP tables; this page does not show a zone map. Not the official USDA Plant Hardiness Zone Map (official map: planthardiness.ars.usda.gov).

Does the new zone change Oklahoma City's frost dates?

No. Hardiness zones are based only on the average coldest winter temperature. They say nothing about when spring and fall frosts happen. Oklahoma City's frost dates come from NOAA's 1991–2020 frost probabilities, which did not change with the 2023 zone map. Use your zone to pick perennials that will survive winter, and your frost dates to time planting.

Why do Oklahoma City frost dates differ between websites?

You may see Apr 10 given as Oklahoma City's last frost date. That's the 30%-risk date, meaning about 3 years in 10 still have a 32°F night after it. Our headline date is Apr 4, the 50% (median) date.

Apr 20 is the 10%-risk, or 'safer', date. Only about 1 year in 10 has a 32°F night after it.

Apr 15 is the 50% date for a 36°F night (frost possible on plants), not a 32°F freeze. Sites that treat 36°F as the danger line show later dates.

The choice of weather station matters too. The 5 stations within 25 miles of the city center that pass our quality rules give typical (50%) last 32°F frost dates from Mar 31 to Apr 4; see the table below.

Which weather station is this based on?

Station

Oklahoma City Will Rogers Airport (NOAA USW00013967, WBAN/ASOS-AWOS)

Distance

7.3 mi SW of the city center

Elevation

1,285 ft; city center 1,196 ft (USGS), difference +89 ft

Record

NOAA completeness flag S, 29 of 30 years (1991–2020)

Confidence

High (rule)

Confidence: High. At 7.3 miles from the city center and only 89 ft off in elevation, with frost statistics that meet our completeness rule (NOAA flag S, 29 of 30 years), this station is a close match.

Oklahoma City planting dates at a glance

Balanced dates use the 30%-risk last-frost date as the anchor. The Oklahoma City planting calendar has typical and safe dates, fall planting and a month-by-month list for 26 vegetables.

When to plant tomatoes in Oklahoma City · Fall planting dates for Oklahoma City

Frost dates near Oklahoma City

All Oklahoma cities

Frequently asked questions

What is the average last frost date in Oklahoma City?

The typical (median, 50%) last 32°F night in Oklahoma City is Apr 4, based on NOAA 1991–2020 normals at Oklahoma City Will Rogers Airport. For a safer target, use Apr 20; after that, only about 1 year in 10 still has a freeze.

When is the first frost in Oklahoma City?

The first 32°F night typically arrives by Nov 2. About 1 year in 10, it comes as early as Oct 21. A 36°F night (frost possible on plants) typically shows up around Oct 26.

What growing zone is Oklahoma City, Oklahoma?

On the current 2023 USDA map, Oklahoma City is in hardiness zone 7b. Older references based on the 2012 map may say 7a, which covered most of the city then.

Is it too early to plant in Oklahoma City?

For frost-tender plants, yes if it's before Apr 4: until then, the odds of another 32°F night are better than even. Between Apr 4 and Apr 20, the risk falls from 50% to 10%. Cool-season crops like peas and lettuce can go in weeks earlier; see the planting calendar.

What temperature is a killing frost?

A light frost is enough to kill tender crops such as tomatoes. CSU Extension describes 28–32°F as a light frost and anything below 28°F as a heavy frost. We report NOAA odds at three thresholds: 36°F (frost possible on plants), 32°F (freeze, our headline) and 28°F (hard freeze).

Is first frost the same as first freeze?

Not exactly. A freeze is about the air reaching 32°F. Frost is ice on surfaces, which can form on calm, clear nights while the air is still a few degrees above freezing. So in Oklahoma City, the first 36°F night (frost possible on plants) typically comes around Oct 26, ahead of the first 32°F night (Nov 2).

Download & sources

• Add Oklahoma City frost & planting dates to your calendar (.ics, 2027)
• Printable planting calendar (PDF)
• How these numbers are calculated

Data: NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal and daily normals, station USW00013967); USDA Plant Hardiness Zone ZIP tables 2023 and 2012 by the PRISM Group, Oregon State University; Census 2020 ZIP/place relationship file; USGS elevation. Long-term odds, not a forecast. Figures and sentences are generated from these data by fixed rules; see the methodology. Last updated 2026-10-08.