Frost dates for 73747Isabella, OK
The average last spring frost in Isabella is April 7 and the average first fall frost is November 2, giving a typical growing season of about 208 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 7
- Average first fall frost
- Nov 2
- Growing season
- 208 days
Safer after Apr 24 (1-in-10 risk)
Possible by Oct 21 (1-in-10 risk)
Last frost typically in 155 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 3 · Apr 19 · May 3 | Oct 8 · Oct 25 · Nov 6 | 186 days | 100% |
| Frost / freeze (32°F) | Mar 20 · Apr 7 · Apr 24 | Oct 21 · Nov 2 · Nov 16 | 208 days | 100% |
| Hard freeze (28°F) | Mar 6 · Mar 26 · Apr 13 | Oct 28 · Nov 9 · Nov 27 | 229 days | 100% |
Planting calendar for Isabella
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 7 – May 13 |
| Tomatoes | Transplant outdoors | Apr 23 – Jul 13 |
| Peppers | Start seeds indoors | Mar 7 – Apr 7 |
| Peppers | Transplant outdoors | May 7 – Jun 7 |
| Eggplant | Start seeds indoors | Mar 24 – Apr 22 |
| Eggplant | Transplant outdoors | May 7 – Jun 7 |
| Cucumbers | Sow outdoors | May 7 – Jul 23 |
| Summer squash | Sow outdoors | Apr 23 – Jun 7 |
| Winter squash & pumpkins | Sow outdoors | May 7 – Jun 7 |
| Snap beans | Sow outdoors | Apr 23 – Aug 15 |
| Sweet corn | Sow outdoors | Apr 23 – Jul 13 |
| Watermelon & cantaloupe | Sow outdoors | May 7 – Jun 7 |
| Okra | Sow outdoors | Apr 30 – May 23 |
| Peas | Sow outdoors (spring) | Mar 7 – Apr 22 |
| Potatoes | Plant outdoors (spring) | Mar 7 – May 7 |
| Onions | Start seeds indoors (spring) | Jan 24 – Feb 20 |
| Onions | Transplant outdoors (spring) | Mar 24 – Apr 22 |
| Broccoli | Start seeds indoors (spring) | Feb 17 – Mar 23 |
| Broccoli | Transplant outdoors (spring) | Mar 24 – Apr 22 |
| Broccoli | Start seeds indoors (fall) | Jul 3 – Jul 13 |
| Broccoli | Transplant outdoors (fall) | Aug 2 – Aug 13 |
| Cabbage | Start seeds indoors (spring) | Feb 7 – Mar 7 |
| Cabbage | Transplant outdoors (spring) | Mar 7 – Apr 7 |
| Cabbage | Start seeds indoors (fall) | Jun 23 – Jul 23 |
| Cabbage | Transplant outdoors (fall) | Jul 23 – Aug 23 |
| Leaf lettuce | Sow outdoors (spring) | Mar 7 – May 23 |
| Leaf lettuce | Sow outdoors (fall) | Jul 23 – Sep 8 |
| Spinach | Sow outdoors (spring) | Feb 28 – Apr 13 |
| Spinach | Sow outdoors (fall) | Aug 9 – Sep 13 |
| Radishes | Sow outdoors (spring) | Mar 7 – Apr 27 |
| Radishes | Sow outdoors (fall) | Jul 23 – Sep 23 |
| Kale | Sow outdoors (spring) | Mar 24 – Apr 13 |
| Kale | Sow outdoors (fall) | Jul 16 – Aug 23 |
| Carrots | Sow outdoors (spring) | Apr 7 – May 23 |
| Carrots | Sow outdoors (fall) | Jun 23 – Aug 8 |
| Garlic | Plant outdoors (fall) | Oct 23 – Nov 23 |
Where these dates come from
ZIP code 73747 is matched to the NOAA station Okeene, OK, 12.7 km away, at 1,215 ft elevation (81 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Okeene, OK (used) | 1,215 ft | Apr 7 | Nov 2 |
| Fairview 1W Mesonet, OK | 1,328 ft | Apr 5 | Nov 1 |
| Lahoma 1Wsw Mesonet, OK | 1,299 ft | Apr 10 | Oct 31 |
| Helena 1 Sse, OK | 1,350 ft | Apr 9 | Oct 31 |
Frost dates near Isabella
- Okeene, OK 73763 · last Apr 7, first Nov 2
- Ames, OK 73718 · last Apr 7, first Nov 2
- Ringwood, OK 73768 · last Apr 9, first Oct 31
- Cleo Springs, OK 73729 · last Apr 9, first Oct 31
- Meno, OK 73760 · last Apr 9, first Oct 31
- Longdale, OK 73755 · last Apr 14, first Oct 27
- Fairview, OK 73737 · last Apr 5, first Nov 1
- Drummond, OK 73735 · last Apr 6, first Nov 1
Frequently asked questions
- When is the last frost in Isabella, OK?
- For ZIP code 73747, the average last spring frost (32°F) is April 7, based on NOAA 1991-2020 climate normals for the Okeene, OK weather station. There is a 1-in-10 chance of a frost after April 24.
- When is the first frost in Isabella, OK?
- The average first fall frost (32°F) is November 2. There is a 1-in-10 chance of frost by October 21, so tender plants are at risk from that point on.
- How long is the growing season in 73747?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 208 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.