When to plant in Duncan, OK
USDA Zone 8aDuncan, Oklahoma frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 8a, Duncan supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
DUNCAN · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Duncan’s own odds, recorded at DUNCAN.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 24 | Apr 7 | Mar 21 | Oct 16 | Oct 30 | Nov 13 |
| 32°F | Apr 12 | Mar 25 | Mar 3 | Oct 22 | Nov 7 | Nov 23 |
| 28°F | Mar 31 | Mar 11 | Feb 24 | Oct 31 | Nov 16 | Dec 4 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Duncan, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 34 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Duncan planting FAQ
When is the last spring frost in Duncan, OK?
Duncan's average last spring frost falls near March 25 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Duncan, OK?
Expect Duncan's first fall frost near November 7 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Duncan in?
Duncan is in USDA hardiness zone 8a. In zone 8a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Duncan?
Duncan has about 227 frost-free days — a long growing season — between the average last spring frost (March 25) and first fall frost (November 7).
When should I plant tomatoes in Duncan?
For Duncan, sow tomatoes indoors about January 28–February 11 and move the seedlings out around April 1, after the last spring frost.
Never miss a window in Duncan
An email when it’s time to start seeds, transplant, and sow — timed to Duncan’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Lawton · 45 km
- Chickasha · 62 km
- Burkburnett · 72 km
- Wichita Falls · 82 km
- Ardmore · 82 km
- Newcastle · 91 km
- Norman · 101 km
- Mustang · 103 km
Frost dates recorded at DUNCAN, 2 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Duncan, OK — Frost Dates & Zone 8a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00342660. Retrieved from https://blissgarden.com/oklahoma/duncan.