When Is the Last Frost in Oklahoma?
The average last spring frost in Oklahoma falls between March 28 and April 11 for most ZIP codes, with a statewide median of April 4. At the average date a later frost is still a coin flip, so tender plants wait for the safer 90% date.
| City | Last frost | 90% safe after | First frost | Growing season |
|---|---|---|---|---|
| Oklahoma City | Apr 4 | Apr 20 | Nov 2 | 213 days |
| Tulsa | Mar 31 | Apr 15 | Nov 4 | 220 days |
| Norman | Mar 31 | Apr 17 | Nov 5 | 219 days |
| Broken Arrow | Apr 1 | Apr 20 | Nov 1 | 212 days |
| Edmond | Apr 10 | Apr 30 | Oct 28 | 199 days |
| Lawton | Mar 26 | Apr 14 | Nov 7 | 225 days |
| Moore | Mar 31 | Apr 17 | Nov 5 | 219 days |
| Midwest City | Apr 2 | Apr 18 | Nov 5 | 217 days |
| Enid | Apr 6 | Apr 21 | Nov 1 | 209 days |
| Stillwater | Apr 5 | Apr 21 | Oct 30 | 206 days |
| Bartlesville | Apr 11 | Apr 30 | Oct 24 | 195 days |
| Muskogee | Apr 2 | Apr 20 | Nov 2 | 216 days |
| Shawnee | Mar 30 | Apr 16 | Nov 5 | 221 days |
| Ardmore | Mar 18 | Apr 9 | Nov 10 | 238 days |
| Ponca City | Apr 10 | Apr 27 | Oct 27 | 200 days |
| Duncan | Mar 25 | Apr 12 | Nov 7 | 225 days |
| Durant | Mar 31 | Apr 19 | Nov 5 | 221 days |
| Claremore | Apr 7 | Apr 24 | Oct 30 | 205 days |
Last and first frost: 50% (median) dates of the last spring and first fall 32 °F night. 90% safe after: only a 10% chance of a later spring frost. First frost dates in January fall in the following winter. Each city uses the NOAA station nearest the ZIP code closest to its center.
Across all 193 Oklahoma weather stations with frost records, median last frost dates run from March 15 at Ardmore, OK to April 26 at Boise City 2 E, OK. Elevation, valleys that collect cold air and distance from large water bodies explain most of the spread, so a garden a few miles from a listed city can differ by a week or more. The ZIP code lookup above uses the same NOAA data as the frost date calculator for every US ZIP code.
When Is the First Frost in Oklahoma?
The average first fall frost in Oklahoma arrives between October 27 and November 6 for most ZIP codes, with a median of November 2. Tomatoes, peppers, basil and squash are damaged at 32 °F, so harvest or cover them before then.
Fall frost can come early: Oklahoma City has a 10% chance of frost before October 21, Tulsa has a 10% chance of frost before October 20 and Norman has a 10% chance of frost before October 21. Hardy crops such as kale, spinach and cabbage tolerate light frosts and keep producing after the first frost date.
When to Plant Tomatoes in Oklahoma?
Transplant tomatoes in Oklahoma 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Apr 11 – Apr 18 in Oklahoma City, Apr 7 – Apr 14 in Tulsa and Apr 7 – Apr 14 in Norman. Start seeds indoors 6 to 8 weeks before the last frost.
| City | Start seeds indoors | Transplant outdoors | Lowest-risk transplant |
|---|---|---|---|
| Oklahoma City | Feb 7 – Feb 21 | Apr 11 – Apr 18 | after Apr 20 |
| Tulsa | Feb 3 – Feb 17 | Apr 7 – Apr 14 | after Apr 15 |
| Norman | Feb 3 – Feb 17 | Apr 7 – Apr 14 | after Apr 17 |
| Broken Arrow | Feb 4 – Feb 18 | Apr 8 – Apr 15 | after Apr 20 |
| Edmond | Feb 13 – Feb 27 | Apr 17 – Apr 24 | after Apr 30 |
| Lawton | Jan 29 – Feb 12 | Apr 2 – Apr 9 | after Apr 14 |
| Moore | Feb 3 – Feb 17 | Apr 7 – Apr 14 | after Apr 17 |
| Midwest City | Feb 5 – Feb 19 | Apr 9 – Apr 16 | after Apr 18 |
| Enid | Feb 9 – Feb 23 | Apr 13 – Apr 20 | after Apr 21 |
| Stillwater | Feb 8 – Feb 22 | Apr 12 – Apr 19 | after Apr 21 |
| Bartlesville | Feb 14 – Feb 28 | Apr 18 – Apr 25 | after Apr 30 |
| Muskogee | Feb 5 – Feb 19 | Apr 9 – Apr 16 | after Apr 20 |
| Shawnee | Feb 2 – Feb 16 | Apr 6 – Apr 13 | after Apr 16 |
| Ardmore | Jan 21 – Feb 4 | Mar 25 – Apr 1 | after Apr 9 |
| Ponca City | Feb 13 – Feb 27 | Apr 17 – Apr 24 | after Apr 27 |
| Duncan | Jan 28 – Feb 11 | Apr 1 – Apr 8 | after Apr 12 |
| Durant | Feb 3 – Feb 17 | Apr 7 – Apr 14 | after Apr 19 |
| Claremore | Feb 10 – Feb 24 | Apr 14 – Apr 21 | after Apr 24 |
Indoors: 6–8 weeks before the average last frost. Outdoors: 1–2 weeks after it. Lowest-risk: after the date with only a 10% chance of a later frost. Rules of thumb; check the 10-day forecast and wait for soil near 60 °F.
Tomatoes stall below about 50 °F at night and are killed by frost, so a week or two of waiting after the average date costs little. The tomato plant care guide covers light, watering and feeding once plants are in the ground.
What Can You Plant in Oklahoma City and When?
Oklahoma City's average last frost of April 4 anchors its spring planting calendar: peas and spinach go in from February 21, broccoli and lettuce transplants from March 7, and tomatoes, peppers and squash after April 11.
| Crop | Start seeds indoors | Plant outdoors | Frost tolerance |
|---|---|---|---|
| Peas | — | Feb 21 – Mar 7direct sow, 4–6 weeks before last frost | hardy |
| Spinach | — | Feb 21 – Mar 14direct sow, 3–6 weeks before last frost | hardy |
| Radishes | — | Feb 28 – Mar 14direct sow, 3–5 weeks before last frost | hardy |
| Onions (sets) | — | Mar 7 – Mar 21plant, 2–4 weeks before last frost | hardy |
| Potatoes | — | Mar 7 – Mar 21plant, 2–4 weeks before last frost | half-hardy |
| Broccoli & cabbage | Feb 7 – Feb 21 | Mar 7 – Mar 21transplant, 2–4 weeks before last frost | hardy |
| Lettuce | Feb 21 – Mar 7 | Mar 7 – Mar 21transplant, 2–4 weeks before last frost | hardy |
| Beets | — | Mar 7 – Mar 21direct sow, 2–4 weeks before last frost | half-hardy |
| Carrots | — | Mar 14 – Mar 21direct sow, 2–3 weeks before last frost | half-hardy |
| Tomatoes | Feb 7 – Feb 21 | Apr 11 – Apr 18transplant, 1–2 weeks after last frost | tender |
| Basil | Feb 7 – Feb 21 | Apr 11 – Apr 25transplant, 1–3 weeks after last frost | tender |
| Peppers | Jan 24 – Feb 7 | Apr 18 – Apr 25transplant, 2–3 weeks after last frost | tender |
| Eggplant | Jan 24 – Feb 7 | Apr 18 – Apr 25transplant, 2–3 weeks after last frost | tender |
| Green beans | — | Apr 11 – Apr 25direct sow, 1–3 weeks after last frost | tender |
| Sweet corn | — | Apr 11 – Apr 25direct sow, 1–3 weeks after last frost | tender |
| Cucumbers | Mar 7 – Mar 14 | Apr 11 – Apr 25transplant, 1–3 weeks after last frost | tender |
| Squash & zucchini | Mar 7 – Mar 14 | Apr 11 – Apr 25transplant, 1–3 weeks after last frost | tender |
| Watermelon | Mar 7 – Mar 14 | Apr 18 – Apr 25transplant, 2–3 weeks after last frost | tender |
Dates for Oklahoma City (last frost Apr 4, NOAA station Oklahoma City Will Rogers AP, OK, 7 miles from ZIP 73102). General rules of thumb; wait for soil near 50 °F for most seeds and 60 °F for beans, corn and squash.
How Long Is the Growing Season in Oklahoma?
The frost-free growing season in Oklahoma lasts about 196 to 224 days for most ZIP codes, with a median of 212 days. Among the listed cities, Bartlesville has the shortest season at 195 days and Ardmore the longest at 238.
Season length decides which varieties ripen: compare it with the “days to maturity” on seed packets, counted from transplanting for tomatoes and peppers. NOAA stations in Oklahoma range from 173 days at Boise City 2 E, OK to 244 days at Ardmore, OK. Planning beds before the season starts helps in short seasons — a plant spacing calculator for vegetable beds shows how many transplants fit.
What Hardiness Zones Are in Oklahoma?
Oklahoma spans USDA hardiness zones 6b to 8a, with zone 7b the most common. Zones describe winter cold and decide which perennials survive, while frost dates set when to plant annual vegetables and flowers.
The Oklahoma planting zone map with the zone of each city shows how the zones are spread across the state and which plants are hardy in all of them.
Frequently Asked Questions
- When is the last frost in Oklahoma?
- The average last spring frost in Oklahoma falls between March 28 and April 11 for most ZIP codes, with a statewide median of April 4. Among major cities it ranges from March 18 in Ardmore to April 11 in Bartlesville.
- When is the last frost in Oklahoma City, Oklahoma?
- Oklahoma City's average last spring frost is April 4, and by April 20 the chance of a later frost drops to 10%. Its first fall frost averages November 2, giving a 213-day growing season (NOAA station Oklahoma City Will Rogers AP, OK).
- When should you plant tomatoes in Oklahoma?
- Transplant tomatoes in Oklahoma 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: Apr 11 – Apr 18 in Oklahoma City, Apr 7 – Apr 14 in Tulsa and Apr 7 – Apr 14 in Norman. Start seeds indoors 6 to 8 weeks before the last frost.
- When is the first frost in Oklahoma?
- The average first fall frost in Oklahoma arrives between October 27 and November 6 for most ZIP codes, with a median of November 2. Harvest tender crops such as tomatoes, peppers and basil before then or cover them on cold nights.
- How long is the growing season in Oklahoma?
- The frost-free growing season in Oklahoma lasts about 196 to 224 days for most ZIP codes, with a median of 212 days, from 195 days in Bartlesville to 238 days in Ardmore.
Frost data: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (32 °F freeze dates by probability). ZIP code and city locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. Planting windows are general rules of thumb. PlantoScan is not affiliated with or endorsed by these agencies.