Frost dates for 66538Seneca, KS
The average last spring frost in Seneca is April 22 and the average first fall frost is October 13, giving a typical growing season of about 173 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 22
- Average first fall frost
- Oct 13
- Growing season
- 173 days
Safer after May 2 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 177 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 19 · Apr 30 · May 10 | Sep 19 · Oct 3 · Oct 16 | 156 days | 100% |
| Frost / freeze (32°F) | Apr 10 · Apr 22 · May 2 | Sep 27 · Oct 13 · Oct 25 | 173 days | 100% |
| Hard freeze (28°F) | Apr 2 · Apr 14 · Apr 25 | Oct 6 · Oct 23 · Nov 3 | 191 days | 100% |
Planting calendar for Seneca
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 22 – May 28 |
| Tomatoes | Transplant outdoors | May 8 – Jun 23 |
| Peppers | Start seeds indoors | Mar 22 – Apr 22 |
| Peppers | Transplant outdoors | May 22 – Jun 22 |
| Eggplant | Start seeds indoors | Apr 8 – May 7 |
| Eggplant | Transplant outdoors | May 22 – Jun 22 |
| Cucumbers | Sow outdoors | May 22 – Jul 3 |
| Summer squash | Sow outdoors | May 8 – Jun 22 |
| Winter squash & pumpkins | Sow outdoors | May 22 – Jun 22 |
| Snap beans | Sow outdoors | May 8 – Jul 26 |
| Sweet corn | Sow outdoors | May 8 – Jun 23 |
| Watermelon & cantaloupe | Sow outdoors | May 22 – Jun 22 |
| Okra | Sow outdoors | May 15 – Jun 7 |
| Peas | Sow outdoors (spring) | Mar 22 – May 7 |
| Potatoes | Plant outdoors (spring) | Mar 22 – May 22 |
| Onions | Start seeds indoors (spring) | Feb 8 – Mar 7 |
| Onions | Transplant outdoors (spring) | Apr 8 – May 7 |
| Broccoli | Start seeds indoors (spring) | Mar 4 – Apr 7 |
| Broccoli | Transplant outdoors (spring) | Apr 8 – May 7 |
| Broccoli | Start seeds indoors (fall) | Jun 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Feb 22 – Mar 22 |
| Cabbage | Transplant outdoors (spring) | Mar 22 – Apr 22 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Mar 22 – Jun 7 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 15 – Apr 28 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Mar 22 – May 12 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 8 – Apr 28 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | Apr 22 – Jun 7 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 66538 is matched to the NOAA station Baileyville, KS, 13.1 km away, at 1,296 ft elevation (59 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Baileyville, KS (used) | 1,296 ft | Apr 22 | Oct 13 |
| Centralia, KS | 1,320 ft | Apr 19 | Oct 19 |
| Frankfort 6Ne, KS | 1,264 ft | Apr 20 | Oct 18 |
| Pawnee City, NE | 1,189 ft | Apr 22 | Oct 15 |
Frost dates near Seneca
- Oneida, KS 66522 · last Apr 22, first Oct 15
- Baileyville, KS 66404 · last Apr 22, first Oct 13
- Bern, KS 66408 · last Apr 22, first Oct 15
- Centralia, KS 66415 · last Apr 19, first Oct 19
- Sabetha, KS 66534 · last Apr 18, first Oct 17
- Axtell, KS 66403 · last Apr 22, first Oct 13
- Corning, KS 66417 · last Apr 19, first Oct 19
- Goff, KS 66428 · last Apr 19, first Oct 19
Frequently asked questions
- When is the last frost in Seneca, KS?
- For ZIP code 66538, the average last spring frost (32°F) is April 22, based on NOAA 1991-2020 climate normals for the Baileyville, KS weather station. There is a 1-in-10 chance of a frost after May 2.
- When is the first frost in Seneca, KS?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 66538?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 173 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.