Frost dates for 66002Atchison, KS
The average last spring frost in Atchison is April 11 and the average first fall frost is October 29, giving a typical growing season of about 199 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 11
- Average first fall frost
- Oct 29
- Growing season
- 199 days
Safer after Apr 23 (1-in-10 risk)
Possible by Oct 15 (1-in-10 risk)
Last frost typically in 159 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 7 · Apr 21 · May 3 | Oct 2 · Oct 20 · Oct 31 | 180 days | 100% |
| Frost / freeze (32°F) | Mar 29 · Apr 11 · Apr 23 | Oct 15 · Oct 29 · Nov 10 | 199 days | 100% |
| Hard freeze (28°F) | Mar 15 · Apr 1 · Apr 14 | Oct 22 · Nov 5 · Nov 21 | 218 days | 100% |
Planting calendar for Atchison
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 11 – May 17 |
| Tomatoes | Transplant outdoors | Apr 27 – Jul 9 |
| Peppers | Start seeds indoors | Mar 11 – Apr 11 |
| Peppers | Transplant outdoors | May 11 – Jun 11 |
| Eggplant | Start seeds indoors | Mar 28 – Apr 26 |
| Eggplant | Transplant outdoors | May 11 – Jun 11 |
| Cucumbers | Sow outdoors | May 11 – Jul 19 |
| Summer squash | Sow outdoors | Apr 27 – Jun 11 |
| Winter squash & pumpkins | Sow outdoors | May 11 – Jun 11 |
| Snap beans | Sow outdoors | Apr 27 – Aug 11 |
| Sweet corn | Sow outdoors | Apr 27 – Jul 9 |
| Watermelon & cantaloupe | Sow outdoors | May 11 – Jun 11 |
| Okra | Sow outdoors | May 4 – May 27 |
| Peas | Sow outdoors (spring) | Mar 11 – Apr 26 |
| Potatoes | Plant outdoors (spring) | Mar 11 – May 11 |
| Onions | Start seeds indoors (spring) | Jan 28 – Feb 24 |
| Onions | Transplant outdoors (spring) | Mar 28 – Apr 26 |
| Broccoli | Start seeds indoors (spring) | Feb 21 – Mar 27 |
| Broccoli | Transplant outdoors (spring) | Mar 28 – Apr 26 |
| Broccoli | Start seeds indoors (fall) | Jun 29 – Jul 9 |
| Broccoli | Transplant outdoors (fall) | Jul 29 – Aug 9 |
| Cabbage | Start seeds indoors (spring) | Feb 11 – Mar 11 |
| Cabbage | Transplant outdoors (spring) | Mar 11 – Apr 11 |
| Cabbage | Start seeds indoors (fall) | Jun 19 – Jul 19 |
| Cabbage | Transplant outdoors (fall) | Jul 19 – Aug 19 |
| Leaf lettuce | Sow outdoors (spring) | Mar 11 – May 27 |
| Leaf lettuce | Sow outdoors (fall) | Jul 19 – Sep 4 |
| Spinach | Sow outdoors (spring) | Mar 4 – Apr 17 |
| Spinach | Sow outdoors (fall) | Aug 5 – Sep 9 |
| Radishes | Sow outdoors (spring) | Mar 11 – May 1 |
| Radishes | Sow outdoors (fall) | Jul 19 – Sep 19 |
| Kale | Sow outdoors (spring) | Mar 28 – Apr 17 |
| Kale | Sow outdoors (fall) | Jul 12 – Aug 19 |
| Carrots | Sow outdoors (spring) | Apr 11 – May 27 |
| Carrots | Sow outdoors (fall) | Jun 19 – Aug 4 |
| Garlic | Plant outdoors (fall) | Oct 19 – Nov 19 |
Where these dates come from
ZIP code 66002 is matched to the NOAA station Atchison, KS, 2.5 km away, at 945 ft elevation (121 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Atchison, KS (used) | 945 ft | Apr 11 | Oct 29 |
| St Joseph Rosecrans Ap, MO | 818 ft | Apr 19 | Oct 17 |
| Troy 3N, KS | 1,040 ft | Apr 19 | Oct 19 |
| Leavenworth, KS | 870 ft | Apr 12 | Oct 27 |
Frost dates near Atchison
- Rushville, MO 64484 · last Apr 11, first Oct 29
- Lancaster, KS 66041 · last Apr 18, first Oct 17
- Cummings, KS 66016 · last Apr 11, first Oct 29
- De Kalb, MO 64440 · last Apr 11, first Oct 29
- Bendena, KS 66008 · last Apr 19, first Oct 19
- Denton, KS 66017 · last Apr 19, first Oct 19
- Weston, MO 64098 · last Apr 12, first Oct 27
- Nortonville, KS 66060 · last Apr 16, first Oct 22
Frequently asked questions
- When is the last frost in Atchison, KS?
- For ZIP code 66002, the average last spring frost (32°F) is April 11, based on NOAA 1991-2020 climate normals for the Atchison, KS weather station. There is a 1-in-10 chance of a frost after April 23.
- When is the first frost in Atchison, KS?
- The average first fall frost (32°F) is October 29. There is a 1-in-10 chance of frost by October 15, so tender plants are at risk from that point on.
- How long is the growing season in 66002?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 199 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.