Frost dates for 66048Leavenworth, KS
The average last spring frost in Leavenworth is April 12 and the average first fall frost is October 27, giving a typical growing season of about 196 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 12
- Average first fall frost
- Oct 27
- Growing season
- 196 days
Safer after Apr 25 (1-in-10 risk)
Possible by Oct 13 (1-in-10 risk)
Last frost typically in 161 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 8 · Apr 21 · May 3 | Oct 1 · Oct 18 · Oct 30 | 178 days | 100% |
| Frost / freeze (32°F) | Mar 31 · Apr 12 · Apr 25 | Oct 13 · Oct 27 · Nov 7 | 196 days | 100% |
| Hard freeze (28°F) | Mar 18 · Apr 3 · Apr 17 | Oct 23 · Nov 4 · Nov 18 | 215 days | 100% |
Planting calendar for Leavenworth
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 7 |
| 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 17 |
| Summer squash | Sow outdoors | Apr 28 – Jun 12 |
| Winter squash & pumpkins | Sow outdoors | May 12 – Jun 12 |
| Snap beans | Sow outdoors | Apr 28 – Aug 9 |
| Sweet corn | Sow outdoors | Apr 28 – Jul 7 |
| 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 27 – Jul 7 |
| Broccoli | Transplant outdoors (fall) | Jul 27 – Aug 7 |
| Cabbage | Start seeds indoors (spring) | Feb 12 – Mar 12 |
| Cabbage | Transplant outdoors (spring) | Mar 12 – Apr 12 |
| Cabbage | Start seeds indoors (fall) | Jun 17 – Jul 17 |
| Cabbage | Transplant outdoors (fall) | Jul 17 – Aug 17 |
| Leaf lettuce | Sow outdoors (spring) | Mar 12 – May 28 |
| Leaf lettuce | Sow outdoors (fall) | Jul 17 – Sep 2 |
| Spinach | Sow outdoors (spring) | Mar 5 – Apr 18 |
| Spinach | Sow outdoors (fall) | Aug 3 – Sep 7 |
| Radishes | Sow outdoors (spring) | Mar 12 – May 2 |
| Radishes | Sow outdoors (fall) | Jul 17 – Sep 17 |
| Kale | Sow outdoors (spring) | Mar 29 – Apr 18 |
| Kale | Sow outdoors (fall) | Jul 10 – Aug 17 |
| Carrots | Sow outdoors (spring) | Apr 12 – May 28 |
| Carrots | Sow outdoors (fall) | Jun 17 – Aug 2 |
| Garlic | Plant outdoors (fall) | Oct 17 – Nov 17 |
Where these dates come from
ZIP code 66048 is matched to the NOAA station Leavenworth, KS, 3 km away, at 870 ft elevation (42 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Leavenworth, KS (used) | 870 ft | Apr 12 | Oct 27 |
| Leavenworth 3Sw, KS | 871 ft | Apr 19 | Oct 19 |
| Kansas City Intl Ap, MO | 1,005 ft | Apr 13 | Oct 24 |
| Bonner Springs, KS | 850 ft | Apr 16 | Oct 22 |
Frost dates near Leavenworth
- Fort Leavenworth, KS 66027 · last Apr 12, first Oct 27
- Lansing, KS 66043 · last Apr 12, first Oct 27
- Kansas City, MO 64168 · last Apr 12, first Oct 27
- Farley, MO 64028 · last Apr 12, first Oct 27
- Waldron, MO 64092 · last Apr 12, first Oct 27
- Platte City, MO 64079 · last Apr 12, first Oct 27
- Easton, KS 66020 · last Apr 16, first Oct 22
- Weston, MO 64098 · last Apr 12, first Oct 27
Frequently asked questions
- When is the last frost in Leavenworth, KS?
- For ZIP code 66048, the average last spring frost (32°F) is April 12, based on NOAA 1991-2020 climate normals for the Leavenworth, KS weather station. There is a 1-in-10 chance of a frost after April 25.
- When is the first frost in Leavenworth, KS?
- The average first fall frost (32°F) is October 27. There is a 1-in-10 chance of frost by October 13, so tender plants are at risk from that point on.
- How long is the growing season in 66048?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 196 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.