Frost dates for 64644Hamilton, MO
The average last spring frost in Hamilton is April 23 and the average first fall frost is October 17, giving a typical growing season of about 175 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 23
- Average first fall frost
- Oct 17
- Growing season
- 175 days
Safer after May 6 (1-in-10 risk)
Possible by Oct 2 (1-in-10 risk)
Last frost typically in 171 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 21 · May 2 · May 16 | Sep 23 · Oct 7 · Oct 20 | 156 days | 100% |
| Frost / freeze (32°F) | Apr 9 · Apr 23 · May 6 | Oct 2 · Oct 17 · Oct 29 | 175 days | 100% |
| Hard freeze (28°F) | Mar 30 · Apr 13 · Apr 26 | Oct 13 · Oct 26 · Nov 8 | 196 days | 100% |
Planting calendar for Hamilton
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 23 – May 29 |
| Tomatoes | Transplant outdoors | May 9 – Jun 27 |
| Peppers | Start seeds indoors | Mar 23 – Apr 23 |
| Peppers | Transplant outdoors | May 23 – Jun 23 |
| Eggplant | Start seeds indoors | Apr 9 – May 8 |
| Eggplant | Transplant outdoors | May 23 – Jun 23 |
| Cucumbers | Sow outdoors | May 23 – Jul 7 |
| Summer squash | Sow outdoors | May 9 – Jun 23 |
| Winter squash & pumpkins | Sow outdoors | May 23 – Jun 23 |
| Snap beans | Sow outdoors | May 9 – Jul 30 |
| Sweet corn | Sow outdoors | May 9 – Jun 27 |
| Watermelon & cantaloupe | Sow outdoors | May 23 – Jun 23 |
| Okra | Sow outdoors | May 16 – Jun 8 |
| Peas | Sow outdoors (spring) | Mar 23 – May 8 |
| Potatoes | Plant outdoors (spring) | Mar 23 – May 23 |
| Onions | Start seeds indoors (spring) | Feb 9 – Mar 8 |
| Onions | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (spring) | Mar 5 – Apr 8 |
| Broccoli | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (fall) | Jun 17 – Jun 27 |
| Broccoli | Transplant outdoors (fall) | Jul 17 – Jul 28 |
| Cabbage | Start seeds indoors (spring) | Feb 23 – Mar 23 |
| Cabbage | Transplant outdoors (spring) | Mar 23 – Apr 23 |
| Cabbage | Start seeds indoors (fall) | Jun 7 – Jul 7 |
| Cabbage | Transplant outdoors (fall) | Jul 7 – Aug 7 |
| Leaf lettuce | Sow outdoors (spring) | Mar 23 – Jun 8 |
| Leaf lettuce | Sow outdoors (fall) | Jul 7 – Aug 23 |
| Spinach | Sow outdoors (spring) | Mar 16 – Apr 29 |
| Spinach | Sow outdoors (fall) | Jul 24 – Aug 28 |
| Radishes | Sow outdoors (spring) | Mar 23 – May 13 |
| Radishes | Sow outdoors (fall) | Jul 7 – Sep 7 |
| Kale | Sow outdoors (spring) | Apr 9 – Apr 29 |
| Kale | Sow outdoors (fall) | Jun 30 – Aug 7 |
| Carrots | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Carrots | Sow outdoors (fall) | Jun 7 – Jul 23 |
| Garlic | Plant outdoors (fall) | Oct 7 – Nov 7 |
Where these dates come from
ZIP code 64644 is matched to the NOAA station Hamilton 2W, MO, 3.8 km away, at 900 ft elevation (78 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hamilton 2W, MO (used) | 900 ft | Apr 23 | Oct 17 |
| Gallatin 1W, MO | 921 ft | Apr 19 | Oct 21 |
| Cameron, MO | 1,010 ft | Apr 15 | Oct 24 |
| Amity 4 Ne, MO | 974 ft | Apr 19 | Oct 19 |
Frost dates near Hamilton
- Kidder, MO 64649 · last Apr 23, first Oct 17
- Kingston, MO 64650 · last Apr 23, first Oct 17
- Breckenridge, MO 64625 · last Apr 23, first Oct 17
- Winston, MO 64689 · last Apr 19, first Oct 19
- Gallatin, MO 64640 · last Apr 19, first Oct 21
- Altamont, MO 64620 · last Apr 19, first Oct 21
- Cowgill, MO 64637 · last Apr 23, first Oct 17
- Polo, MO 64671 · last Apr 23, first Oct 17
Frequently asked questions
- When is the last frost in Hamilton, MO?
- For ZIP code 64644, the average last spring frost (32°F) is April 23, based on NOAA 1991-2020 climate normals for the Hamilton 2W, MO weather station. There is a 1-in-10 chance of a frost after May 6.
- When is the first frost in Hamilton, MO?
- The average first fall frost (32°F) is October 17. There is a 1-in-10 chance of frost by October 2, so tender plants are at risk from that point on.
- How long is the growing season in 64644?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 175 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.