Frost dates for 73647Foss, OK
The average last spring frost in Foss is April 13 and the average first fall frost is October 28, giving a typical growing season of about 197 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 13
- Average first fall frost
- Oct 28
- Growing season
- 197 days
Safer after Apr 27 (1-in-10 risk)
Possible by Oct 14 (1-in-10 risk)
First frost typically in 2 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 22 · May 5 | Oct 6 · Oct 20 · Oct 30 | 179 days | 100% |
| Frost / freeze (32°F) | Mar 31 · Apr 13 · Apr 27 | Oct 14 · Oct 28 · Nov 9 | 197 days | 100% |
| Hard freeze (28°F) | Mar 11 · Apr 1 · Apr 18 | Oct 20 · Nov 5 · Nov 19 | 219 days | 100% |
Planting calendar for Foss
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 13 – May 19 |
| Tomatoes | Transplant outdoors | Apr 29 – Jul 8 |
| Peppers | Start seeds indoors | Mar 13 – Apr 13 |
| Peppers | Transplant outdoors | May 13 – Jun 13 |
| Eggplant | Start seeds indoors | Mar 30 – Apr 28 |
| Eggplant | Transplant outdoors | May 13 – Jun 13 |
| Cucumbers | Sow outdoors | May 13 – Jul 18 |
| Summer squash | Sow outdoors | Apr 29 – Jun 13 |
| Winter squash & pumpkins | Sow outdoors | May 13 – Jun 13 |
| Snap beans | Sow outdoors | Apr 29 – Aug 10 |
| Sweet corn | Sow outdoors | Apr 29 – Jul 8 |
| Watermelon & cantaloupe | Sow outdoors | May 13 – Jun 13 |
| Okra | Sow outdoors | May 6 – May 29 |
| Peas | Sow outdoors (spring) | Mar 13 – Apr 28 |
| Potatoes | Plant outdoors (spring) | Mar 13 – May 13 |
| Onions | Start seeds indoors (spring) | Jan 30 – Feb 26 |
| Onions | Transplant outdoors (spring) | Mar 30 – Apr 28 |
| Broccoli | Start seeds indoors (spring) | Feb 23 – Mar 29 |
| Broccoli | Transplant outdoors (spring) | Mar 30 – Apr 28 |
| Broccoli | Start seeds indoors (fall) | Jun 28 – Jul 8 |
| Broccoli | Transplant outdoors (fall) | Jul 28 – Aug 8 |
| Cabbage | Start seeds indoors (spring) | Feb 13 – Mar 13 |
| Cabbage | Transplant outdoors (spring) | Mar 13 – Apr 13 |
| Cabbage | Start seeds indoors (fall) | Jun 18 – Jul 18 |
| Cabbage | Transplant outdoors (fall) | Jul 18 – Aug 18 |
| Leaf lettuce | Sow outdoors (spring) | Mar 13 – May 29 |
| Leaf lettuce | Sow outdoors (fall) | Jul 18 – Sep 3 |
| Spinach | Sow outdoors (spring) | Mar 6 – Apr 19 |
| Spinach | Sow outdoors (fall) | Aug 4 – Sep 8 |
| Radishes | Sow outdoors (spring) | Mar 13 – May 3 |
| Radishes | Sow outdoors (fall) | Jul 18 – Sep 18 |
| Kale | Sow outdoors (spring) | Mar 30 – Apr 19 |
| Kale | Sow outdoors (fall) | Jul 11 – Aug 18 |
| Carrots | Sow outdoors (spring) | Apr 13 – May 29 |
| Carrots | Sow outdoors (fall) | Jun 18 – Aug 3 |
| Garlic | Plant outdoors (fall) | Oct 18 – Nov 18 |
Where these dates come from
ZIP code 73647 is matched to the NOAA station Clinton, OK, 18.2 km away, at 1,570 ft elevation (64 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Clinton, OK (used) | 1,570 ft | Apr 13 | Oct 28 |
| Bessie 4Wnw Mesonet, OK | 1,676 ft | Apr 3 | Nov 1 |
| Butler 5Sw Mesonet, OK | 1,706 ft | Apr 9 | Oct 28 |
| Hammon 3 Ssw, OK | 1,820 ft | Apr 16 | Oct 23 |
Frost dates near Foss
- Canute, OK 73626 · last Apr 5, first Nov 4
- Burns Flat, OK 73624 · last Apr 5, first Nov 4
- Bessie, OK 73622 · last Apr 13, first Oct 28
- Clinton, OK 73601 · last Apr 13, first Oct 28
- Dill City, OK 73641 · last Apr 5, first Nov 4
- Butler, OK 73625 · last Apr 9, first Oct 28
- Elk City, OK 73648 · last Apr 5, first Nov 2
- Arapaho, OK 73620 · last Apr 13, first Oct 28
Frequently asked questions
- When is the last frost in Foss, OK?
- For ZIP code 73647, the average last spring frost (32°F) is April 13, based on NOAA 1991-2020 climate normals for the Clinton, OK weather station. There is a 1-in-10 chance of a frost after April 27.
- When is the first frost in Foss, OK?
- The average first fall frost (32°F) is October 28. There is a 1-in-10 chance of frost by October 14, so tender plants are at risk from that point on.
- How long is the growing season in 73647?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 197 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.