USDA zone 7a in Oklahoma
USDA plant hardiness zone 7a covers 48 locations across Oklahoma (average annual extreme minimum 0 to 5 °F): Alva, OK, Avant, OK, Bartlesville, OK, Billings, OK, Blackwell, OK, Buffalo, OK, and 42 more. Average last spring frost across this group ranges March 31 (Avant) to April 21 (Woodward), and growing seasons run 179–220 days (Freedom to Collinsville) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Oklahoma location's own frost dates; the printable planting calendar uses Ponca, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Mar 31–Apr 21avg, 32°F
- First frost range
- Oct 17–Nov 5avg, 32°F
- Growing season range
- 179–220days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Alva | — | Alva 1w | Apr 10 | Oct 28 | 199 |
| Avant | Barnsdall | Barnsdall | Mar 31 | Oct 31 | 212 |
| Bartlesville | Dewey, Copan, Ramona, Ochelata | Bartlesville F P Fld | Apr 12 | Oct 21 | 192 |
| Billings | Garber, Covington, Lamont, Red Rock, Hunter | Billings | Apr 15 | Oct 26 | 194 |
| Blackwell | Tonkawa, Nardin, Braman, Deer Creek | Blackwell 1ssw | Apr 12 | Oct 29 | 199 |
| Buffalo | — | Buffalo 1sw Mesonet | Apr 13 | Oct 25 | 195 |
| Butler | — | Butler 5sw Mesonet | Apr 9 | Oct 28 | 199 |
| Canton | Oakwood, Hitchcock | Watonga | Apr 14 | Oct 27 | 194 |
| Carmen | Ringwood, Cleo Springs, Helena, Goltry, Aline, Meno | Helena 1 Sse | Apr 9 | Oct 31 | 205 |
| Cayuga | Jane, Anderson, Ginger Blue | Anderson | Apr 15 | Oct 23 | 191 |
| Chance | Leach, Twin Oaks, Colcord, Kansas, Oaks | Kansas 2 Ne | Mar 31 | Nov 2 | 216 |
| Cherokee | — | Cherokee 1ssw Mesonet | Apr 10 | Oct 29 | 201 |
| Chester | Vici, Mutual, Camargo, Sharon | Mutual | Apr 19 | Oct 26 | 188 |
| Cheyenne | Reydon | Cheyenne 6sw Mesonet | Apr 3 | Nov 3 | 212 |
| Claremore | Sequoyah, Chelsea, Oologah, Talala | Claremore 2 Ene | Apr 7 | Oct 30 | 205 |
| Collinsville | Vera | Tulsa Intl Ap | Mar 31 | Nov 4 | 220 |
| Durham | — | Arnett 8wsw Mesonet | Apr 9 | Oct 27 | 200 |
| Enid | Waukomis, Carrier, Pond Creek, Hillsdale, Drummond, Kremlin, +1 more | Enid | Apr 6 | Nov 1 | 209 |
| Erick | — | Erick | Apr 11 | Oct 26 | 197 |
| Fairview | — | Fairview 1w Mesonet | Apr 5 | Nov 1 | 208 |
| Freedom | — | Freedom | Apr 19 | Oct 17 | 179 |
| Hammon | — | Hammon 3 Ssw | Apr 16 | Oct 23 | 191 |
| Hennessey | Crescent, Bison, Marshall, Dover, Douglas, Loyal | Hennessey 4 Ese | Apr 14 | Oct 30 | 198 |
| Hominy | Oilton, Hallett, Jennings, Osage, Maramec, Terlton | Mannford 6 Nw | Apr 6 | Oct 29 | 207 |
| Hopeton | — | Alva 7ssw Mesonet | Apr 11 | Oct 26 | 198 |
| Isabella | Okeene, Ames, Longdale | Okeene | Apr 7 | Nov 2 | 208 |
| Kaw | Newkirk, Silverdale, Foraker | Newkirk 5ne | Apr 16 | Oct 26 | 192 |
| Kenwood | White Oak, Vinita, Adair, Ketchum, Langley, Disney, +4 more | Spavinaw | Apr 7 | Nov 2 | 209 |
| Lahoma | — | Lahoma 1wsw Mesonet | Apr 10 | Oct 31 | 204 |
| Langston | Mulhall | Guthrie Muni Ap | Apr 3 | Nov 1 | 211 |
| Leedey | — | Camargo 4wnw Mesonet | Apr 15 | Oct 23 | 189 |
| Medford | — | Medford 1sw Mesonet | Apr 10 | Oct 28 | 199 |
| Miami | Fairland, Bluejacket, North Miami | Miami | Apr 6 | Oct 27 | 203 |
| Milfay | — | Bristow | Apr 9 | Oct 25 | 196 |
| Nash | Wakita, Jet, Byron | Great Salt Plains Dam | Apr 5 | Nov 1 | 209 |
| Nowata | — | Nowata | Apr 4 | Nov 1 | 210 |
| Pawhuska | Wynona | Pawhuska | Apr 6 | Oct 29 | 204 |
| Pawnee | Fairfax, Ralston, Burbank | Ralston | Apr 11 | Oct 24 | 196 |
| Perry | Lucien, Orlando | Perry | Apr 4 | Nov 1 | 210 |
| Ponca * | McCord, Marland | Ponca City Muni Ap | Apr 10 | Oct 27 | 200 |
| Pryor Creek | — | Pryor | Apr 5 | Oct 30 | 207 |
| Putnam | — | Putnam 3n Mesonet | Apr 8 | Nov 1 | 204 |
| Rosston | Knowles | Gate | Apr 13 | Oct 28 | 196 |
| Seiling | Taloga | Taloga | Apr 18 | Oct 21 | 185 |
| Stillwater | Glencoe, Morrison | Stillwater Rgnl Ap | Apr 3 | Oct 31 | 209 |
| Waynoka | Dacoma, Quinlan | Waynoka | Apr 12 | Oct 24 | 192 |
| Woodward | Fort Supply, May | Ft Supply 3se | Apr 21 | Oct 19 | 179 |
| Yale | Ripley | Cushing | Apr 1 | Nov 5 | 217 |
* Ponca is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Ponca, representative)
Computed from Ponca's average frost dates — the median-season location in this Oklahomazone 7a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Feb 13 – Feb 27 | Apr 17 – Apr 24 | Jun 16 – Jul 6 | — | matures comfortably |
| Pepper | Very tender | Jan 30 – Feb 13 | Apr 24 – May 1 | Jun 23 – Jul 23 | — | matures comfortably |
| Cucumber | Tender | Mar 13 – Mar 20 | Apr 17 – Apr 24 | Jun 6 – Jun 26 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 17 – Apr 24 | Jun 1 – Jun 16 | — | matures comfortably |
| Bush bean | Tender | — | Apr 17 – Apr 24 | Jun 6 – Jun 16 | Aug 28 – Sep 7 | matures comfortably |
| Sweet corn | Tender | — | Apr 10 – Apr 24 | Jun 9 – Jul 9 | — | matures comfortably |
| Basil | Very tender | Feb 27 – Mar 13 | Apr 17 – Apr 24 | May 17 – Jun 1 | — | matures comfortably |
| Lettuce | Half-hardy | Feb 27 – Mar 13 | Mar 13 – Mar 27 | Apr 27 – May 12 | Aug 14 – Aug 29 | matures comfortably |
| Pea | Hardy | — | Feb 27 – Mar 13 | Apr 23 – May 8 | Aug 4 – Aug 19 | matures comfortably |
| Spinach | Hardy | — | Feb 27 – Mar 13 | Apr 8 – Apr 18 | Aug 24 – Sep 3 | matures comfortably |
| Carrot | Half-hardy | — | Mar 20 – Mar 27 | May 19 – Jun 8 | Jul 25 – Aug 14 | matures comfortably |
| Broccoli | Half-hardy | Feb 13 – Feb 27 | Mar 13 – Mar 27 | May 7 – May 27 | Jul 30 – Aug 19 | matures comfortably |
Which crops fit this growing season
Using Ponca's own 200-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Ponca)
From NOAA's 1991–2020 Climate Normals at station USW00013969. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 21 | May 5 | Oct 18 | Nov 1 | 179 |
| 32°F (freeze) | Apr 10 | Apr 27 | Oct 27 | Nov 10 | 200 |
| 28°F | Mar 29 | Apr 15 | Nov 5 | Nov 20 | 222 |
| 24°F | Mar 17 | Apr 4 | Nov 15 | Dec 2 | 243 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 48 locations is 4,867; Ponca's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 4,948 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 7,658 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in Oklahoma
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Oklahoma spans 4 hardiness zones in this dataset — see all Oklahoma locations for the full range, including zones6b, 7b, 8a.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in Oklahoma?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 48 locations in Oklahoma fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Oklahoma's zone 7a is the growing season longest?
- Collinsville runs the longest season on this page at about 220 days; Freedom is shortest at about 179 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Oklahoma's zone 7a?
- Using Ponca's frost dates (this page's median-season location): start seeds indoors about Feb 13 – Feb 27, then transplant outside about Apr 17 – Apr 24. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Oklahoma's zone 7a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 48 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.