Frost dates for 67473Osborne, KS
The average last spring frost in Osborne is April 29 and the average first fall frost is October 12, giving a typical growing season of about 164 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 12
- Growing season
- 164 days
Safer after May 11 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 176 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 25 · May 7 · May 22 | Sep 21 · Oct 2 · Oct 16 | 147 days | 100% |
| Frost / freeze (32°F) | Apr 16 · Apr 29 · May 11 | Sep 28 · Oct 12 · Oct 27 | 164 days | 100% |
| Hard freeze (28°F) | Apr 5 · Apr 19 · May 3 | Oct 7 · Oct 22 · Nov 4 | 182 days | 100% |
Planting calendar for Osborne
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 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 22 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jul 2 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 25 |
| Sweet corn | Sow outdoors | May 15 – Jun 22 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 12 – Jun 22 |
| Broccoli | Transplant outdoors (fall) | Jul 12 – Jul 23 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | Jun 2 – Jul 2 |
| Cabbage | Transplant outdoors (fall) | Jul 2 – Aug 2 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jul 2 – Aug 18 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 19 – Aug 23 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jul 2 – Sep 2 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 25 – Aug 2 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | Jun 2 – Jul 18 |
| Garlic | Plant outdoors (fall) | Oct 2 – Nov 2 |
Where these dates come from
ZIP code 67473 is matched to the NOAA station Alton 1 W, KS, 24.5 km away, at 1,685 ft elevation (130 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Alton 1 W, KS (used) | 1,685 ft | Apr 29 | Oct 12 |
| Glen Elder Lake, KS | 1,500 ft | Apr 29 | Oct 15 |
| Smith Ctr, KS | 1,820 ft | Apr 24 | Oct 15 |
| Kirwin Dam, KS | 1,697 ft | Apr 30 | Oct 7 |
Frost dates near Osborne
- Portis, KS 67474 · last Apr 24, first Oct 15
- Downs, KS 67437 · last Apr 29, first Oct 15
- Tipton, KS 67485 · last Apr 29, first Oct 15
- Alton, KS 67623 · last Apr 29, first Oct 12
- Cawker City, KS 67430 · last Apr 29, first Oct 15
- Gaylord, KS 67638 · last Apr 24, first Oct 15
- Hunter, KS 67452 · last Apr 21, first Oct 17
- Glen Elder, KS 67446 · last Apr 29, first Oct 15
Frequently asked questions
- When is the last frost in Osborne, KS?
- For ZIP code 67473, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Alton 1 W, KS weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Osborne, KS?
- The average first fall frost (32°F) is October 12. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 67473?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 164 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.