Frost dates for 73534Duncan, OK
The average last spring frost in Duncan is March 25 and the average first fall frost is November 7, giving a typical growing season of about 225 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 25
- Average first fall frost
- Nov 7
- Growing season
- 225 days
Safer after Apr 12 (1-in-10 risk)
Possible by Oct 22 (1-in-10 risk)
First frost typically in 12 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Mar 21 · Apr 7 · Apr 24 | Oct 16 · Oct 30 · Nov 13 | 205 days | 100% |
| Frost / freeze (32°F) | Mar 3 · Mar 25 · Apr 12 | Oct 22 · Nov 7 · Nov 23 | 225 days | 100% |
| Hard freeze (28°F) | Feb 24 · Mar 11 · Mar 31 | Oct 31 · Nov 16 · Dec 4 | 249 days | 100% |
Planting calendar for Duncan
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Feb 22 – Apr 30 |
| Tomatoes | Transplant outdoors | Apr 10 – Jul 18 |
| Peppers | Start seeds indoors | Feb 22 – Mar 25 |
| Peppers | Transplant outdoors | Apr 24 – May 25 |
| Eggplant | Start seeds indoors | Mar 11 – Apr 9 |
| Eggplant | Transplant outdoors | Apr 24 – May 25 |
| Cucumbers | Sow outdoors | Apr 24 – Jul 28 |
| Summer squash | Sow outdoors | Apr 10 – May 25 |
| Winter squash & pumpkins | Sow outdoors | Apr 24 – May 25 |
| Snap beans | Sow outdoors | Apr 10 – Aug 20 |
| Sweet corn | Sow outdoors | Apr 10 – Jul 18 |
| Watermelon & cantaloupe | Sow outdoors | Apr 24 – May 25 |
| Okra | Sow outdoors | Apr 17 – May 10 |
| Peas | Sow outdoors (spring) | Feb 22 – Apr 9 |
| Potatoes | Plant outdoors (spring) | Feb 22 – Apr 24 |
| Onions | Start seeds indoors (spring) | Jan 11 – Feb 7 |
| Onions | Transplant outdoors (spring) | Mar 11 – Apr 9 |
| Broccoli | Start seeds indoors (spring) | Feb 4 – Mar 10 |
| Broccoli | Transplant outdoors (spring) | Mar 11 – Apr 9 |
| Broccoli | Start seeds indoors (fall) | Jul 8 – Jul 18 |
| Broccoli | Transplant outdoors (fall) | Aug 7 – Aug 18 |
| Cabbage | Start seeds indoors (spring) | Jan 25 – Feb 22 |
| Cabbage | Transplant outdoors (spring) | Feb 22 – Mar 25 |
| Cabbage | Start seeds indoors (fall) | Jun 28 – Jul 28 |
| Cabbage | Transplant outdoors (fall) | Jul 28 – Aug 28 |
| Leaf lettuce | Sow outdoors (spring) | Feb 22 – May 10 |
| Leaf lettuce | Sow outdoors (fall) | Jul 28 – Sep 13 |
| Spinach | Sow outdoors (spring) | Feb 15 – Mar 31 |
| Spinach | Sow outdoors (fall) | Aug 14 – Sep 18 |
| Radishes | Sow outdoors (spring) | Feb 22 – Apr 14 |
| Radishes | Sow outdoors (fall) | Jul 28 – Sep 28 |
| Kale | Sow outdoors (spring) | Mar 11 – Mar 31 |
| Kale | Sow outdoors (fall) | Jul 21 – Aug 28 |
| Carrots | Sow outdoors (spring) | Mar 25 – May 10 |
| Carrots | Sow outdoors (fall) | Jun 28 – Aug 13 |
| Garlic | Plant outdoors (fall) | Oct 28 – Nov 28 |
Where these dates come from
ZIP code 73534 is matched to the NOAA station Duncan, OK, 2.4 km away, at 1,125 ft elevation (20 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Duncan, OK (used) | 1,125 ft | Mar 25 | Nov 7 |
| Velma 7Nw Mesonet, OK | 1,118 ft | Mar 28 | Nov 7 |
| Acme Mesonet, OK | 1,302 ft | Apr 4 | Oct 31 |
| Walters, OK | 1,005 ft | Apr 1 | Nov 5 |
Frost dates near Duncan
- Duncan, OK 73533 · last Mar 25, first Nov 7
- Marlow, OK 73055 · last Mar 25, first Nov 7
- Comanche, OK 73529 · last Mar 25, first Nov 7
- Rush Springs, OK 73082 · last Apr 4, first Oct 31
- Velma, OK 73491 · last Mar 28, first Nov 7
- Addington, OK 73520 · last Mar 24, first Nov 8
- Sterling, OK 73567 · last Apr 4, first Oct 31
- Hastings, OK 73548 · last Mar 24, first Nov 8
Frequently asked questions
- When is the last frost in Duncan, OK?
- For ZIP code 73534, the average last spring frost (32°F) is March 25, based on NOAA 1991-2020 climate normals for the Duncan, OK weather station. There is a 1-in-10 chance of a frost after April 12.
- When is the first frost in Duncan, OK?
- The average first fall frost (32°F) is November 7. There is a 1-in-10 chance of frost by October 22, so tender plants are at risk from that point on.
- How long is the growing season in 73534?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 225 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.