Frost dates for 66503Manhattan, KS
The average last spring frost in Manhattan is April 22 and the average first fall frost is October 20, giving a typical growing season of about 179 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 22
- Average first fall frost
- Oct 20
- Growing season
- 179 days
Safer after May 5 (1-in-10 risk)
Possible by Oct 4 (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 17 · Apr 30 · May 14 | Sep 25 · Oct 8 · Oct 22 | 161 days | 100% |
| Frost / freeze (32°F) | Apr 8 · Apr 22 · May 5 | Oct 4 · Oct 20 · Nov 1 | 179 days | 100% |
| Hard freeze (28°F) | Mar 28 · Apr 10 · Apr 26 | Oct 15 · Oct 28 · Nov 10 | 198 days | 100% |
Planting calendar for Manhattan
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 30 |
| 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 10 |
| Summer squash | Sow outdoors | May 8 – Jun 22 |
| Winter squash & pumpkins | Sow outdoors | May 22 – Jun 22 |
| Snap beans | Sow outdoors | May 8 – Aug 2 |
| Sweet corn | Sow outdoors | May 8 – Jun 30 |
| 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 20 – Jun 30 |
| Broccoli | Transplant outdoors (fall) | Jul 20 – Jul 31 |
| Cabbage | Start seeds indoors (spring) | Feb 22 – Mar 22 |
| Cabbage | Transplant outdoors (spring) | Mar 22 – Apr 22 |
| Cabbage | Start seeds indoors (fall) | Jun 10 – Jul 10 |
| Cabbage | Transplant outdoors (fall) | Jul 10 – Aug 10 |
| Leaf lettuce | Sow outdoors (spring) | Mar 22 – Jun 7 |
| Leaf lettuce | Sow outdoors (fall) | Jul 10 – Aug 26 |
| Spinach | Sow outdoors (spring) | Mar 15 – Apr 28 |
| Spinach | Sow outdoors (fall) | Jul 27 – Aug 31 |
| Radishes | Sow outdoors (spring) | Mar 22 – May 12 |
| Radishes | Sow outdoors (fall) | Jul 10 – Sep 10 |
| Kale | Sow outdoors (spring) | Apr 8 – Apr 28 |
| Kale | Sow outdoors (fall) | Jul 3 – Aug 10 |
| Carrots | Sow outdoors (spring) | Apr 22 – Jun 7 |
| Carrots | Sow outdoors (fall) | Jun 10 – Jul 26 |
| Garlic | Plant outdoors (fall) | Oct 10 – Nov 10 |
Where these dates come from
ZIP code 66503 is matched to the NOAA station Tuttle Creek Lake, KS, 3 km away, at 1,058 ft elevation (241 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Tuttle Creek Lake, KS (used) | 1,058 ft | Apr 22 | Oct 20 |
| Manhattan, KS | 1,060 ft | Apr 16 | Oct 19 |
| Manhattan Muni Ap, KS | 1,057 ft | Apr 21 | Oct 16 |
| Manhattan 6 Ssw, KS | 1,137 ft | Apr 19 | Oct 17 |
Frost dates near Manhattan
- Manhattan, KS 66506 · last Apr 16, first Oct 19
- Ogden, KS 66517 · last Apr 21, first Oct 16
- Riley, KS 66531 · last Apr 12, first Oct 26
- Saint George, KS 66535 · last Apr 18, first Oct 19
- Olsburg, KS 66520 · last Apr 22, first Oct 20
- Leonardville, KS 66449 · last Apr 19, first Oct 19
- Fostoria, KS 66426 · last Apr 18, first Oct 19
- Fort Riley, KS 66442 · last Apr 12, first Oct 26
Frequently asked questions
- When is the last frost in Manhattan, KS?
- For ZIP code 66503, the average last spring frost (32°F) is April 22, based on NOAA 1991-2020 climate normals for the Tuttle Creek Lake, KS weather station. There is a 1-in-10 chance of a frost after May 5.
- When is the first frost in Manhattan, KS?
- The average first fall frost (32°F) is October 20. There is a 1-in-10 chance of frost by October 4, so tender plants are at risk from that point on.
- How long is the growing season in 66503?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 179 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.