Frost dates for 74022Copan, OK
The average last spring frost in Copan is April 12 and the average first fall frost is October 21, giving a typical growing season of about 192 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 12
- Average first fall frost
- Oct 21
- Growing season
- 192 days
Safer after Apr 28 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 167 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) | Apr 9 · Apr 23 · May 6 | Sep 28 · Oct 12 · Oct 26 | 170 days | 100% |
| Frost / freeze (32°F) | Mar 28 · Apr 12 · Apr 28 | Oct 5 · Oct 21 · Nov 3 | 192 days | 100% |
| Hard freeze (28°F) | Mar 14 · Mar 31 · Apr 16 | Oct 14 · Oct 31 · Nov 14 | 213 days | 100% |
Planting calendar for Copan
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 | Mar 12 – May 18 |
| Tomatoes | Transplant outdoors | Apr 28 – Jul 1 |
| Peppers | Start seeds indoors | Mar 12 – Apr 12 |
| Peppers | Transplant outdoors | May 12 – Jun 12 |
| Eggplant | Start seeds indoors | Mar 29 – Apr 27 |
| Eggplant | Transplant outdoors | May 12 – Jun 12 |
| Cucumbers | Sow outdoors | May 12 – Jul 11 |
| Summer squash | Sow outdoors | Apr 28 – Jun 12 |
| Winter squash & pumpkins | Sow outdoors | May 12 – Jun 12 |
| Snap beans | Sow outdoors | Apr 28 – Aug 3 |
| Sweet corn | Sow outdoors | Apr 28 – Jul 1 |
| Watermelon & cantaloupe | Sow outdoors | May 12 – Jun 12 |
| Okra | Sow outdoors | May 5 – May 28 |
| Peas | Sow outdoors (spring) | Mar 12 – Apr 27 |
| Potatoes | Plant outdoors (spring) | Mar 12 – May 12 |
| Onions | Start seeds indoors (spring) | Jan 29 – Feb 25 |
| Onions | Transplant outdoors (spring) | Mar 29 – Apr 27 |
| Broccoli | Start seeds indoors (spring) | Feb 22 – Mar 28 |
| Broccoli | Transplant outdoors (spring) | Mar 29 – Apr 27 |
| Broccoli | Start seeds indoors (fall) | Jun 21 – Jul 1 |
| Broccoli | Transplant outdoors (fall) | Jul 21 – Aug 1 |
| Cabbage | Start seeds indoors (spring) | Feb 12 – Mar 12 |
| Cabbage | Transplant outdoors (spring) | Mar 12 – Apr 12 |
| Cabbage | Start seeds indoors (fall) | Jun 11 – Jul 11 |
| Cabbage | Transplant outdoors (fall) | Jul 11 – Aug 11 |
| Leaf lettuce | Sow outdoors (spring) | Mar 12 – May 28 |
| Leaf lettuce | Sow outdoors (fall) | Jul 11 – Aug 27 |
| Spinach | Sow outdoors (spring) | Mar 5 – Apr 18 |
| Spinach | Sow outdoors (fall) | Jul 28 – Sep 1 |
| Radishes | Sow outdoors (spring) | Mar 12 – May 2 |
| Radishes | Sow outdoors (fall) | Jul 11 – Sep 11 |
| Kale | Sow outdoors (spring) | Mar 29 – Apr 18 |
| Kale | Sow outdoors (fall) | Jul 4 – Aug 11 |
| Carrots | Sow outdoors (spring) | Apr 12 – May 28 |
| Carrots | Sow outdoors (fall) | Jun 11 – Jul 27 |
| Garlic | Plant outdoors (fall) | Oct 11 – Nov 11 |
Where these dates come from
ZIP code 74022 is matched to the NOAA station Bartlesville F P Fld, OK, 18.3 km away, at 715 ft elevation (79 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Bartlesville F P Fld, OK (used) | 715 ft | Apr 12 | Oct 21 |
| Bartlesville 3, OK | 715 ft | Apr 11 | Oct 24 |
| Coffeyville Wtr Wks, KS | 737 ft | Apr 6 | Nov 1 |
| Nowata, OK | 710 ft | Apr 4 | Nov 1 |
Frost dates near Copan
- Dewey, OK 74029 · last Apr 12, first Oct 21
- Wann, OK 74083 · last Apr 6, first Nov 1
- Caney, KS 67333 · last Apr 6, first Nov 1
- Tyro, KS 67364 · last Apr 6, first Nov 1
- Niotaze, KS 67355 · last Apr 9, first Oct 27
- Bartlesville, OK 74005 · last Apr 12, first Oct 21
- Havana, KS 67347 · last Apr 9, first Oct 27
- Dearing, KS 67340 · last Apr 6, first Nov 1
Frequently asked questions
- When is the last frost in Copan, OK?
- For ZIP code 74022, the average last spring frost (32°F) is April 12, based on NOAA 1991-2020 climate normals for the Bartlesville F P Fld, OK weather station. There is a 1-in-10 chance of a frost after April 28.
- When is the first frost in Copan, OK?
- The average first fall frost (32°F) is October 21. There is a 1-in-10 chance of frost by October 5, so tender plants are at risk from that point on.
- How long is the growing season in 74022?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 192 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.