Frost dates for 65256Harrisburg, MO
The average last spring frost in Harrisburg is April 5 and the average first fall frost is October 31, giving a typical growing season of about 207 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 5
- Average first fall frost
- Oct 31
- Growing season
- 207 days
Safer after Apr 21 (1-in-10 risk)
Possible by Oct 17 (1-in-10 risk)
Last frost typically in 154 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 2 · Apr 18 · May 4 | Oct 6 · Oct 20 · Nov 1 | 184 days | 100% |
| Frost / freeze (32°F) | Mar 19 · Apr 5 · Apr 21 | Oct 17 · Oct 31 · Nov 14 | 207 days | 100% |
| Hard freeze (28°F) | Mar 8 · Mar 26 · Apr 11 | Oct 27 · Nov 9 · Nov 27 | 229 days | 100% |
Planting calendar for Harrisburg
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 5 – May 11 |
| Tomatoes | Transplant outdoors | Apr 21 – Jul 11 |
| Peppers | Start seeds indoors | Mar 5 – Apr 5 |
| Peppers | Transplant outdoors | May 5 – Jun 5 |
| Eggplant | Start seeds indoors | Mar 22 – Apr 20 |
| Eggplant | Transplant outdoors | May 5 – Jun 5 |
| Cucumbers | Sow outdoors | May 5 – Jul 21 |
| Summer squash | Sow outdoors | Apr 21 – Jun 5 |
| Winter squash & pumpkins | Sow outdoors | May 5 – Jun 5 |
| Snap beans | Sow outdoors | Apr 21 – Aug 13 |
| Sweet corn | Sow outdoors | Apr 21 – Jul 11 |
| Watermelon & cantaloupe | Sow outdoors | May 5 – Jun 5 |
| Okra | Sow outdoors | Apr 28 – May 21 |
| Peas | Sow outdoors (spring) | Mar 5 – Apr 20 |
| Potatoes | Plant outdoors (spring) | Mar 5 – May 5 |
| Onions | Start seeds indoors (spring) | Jan 22 – Feb 18 |
| Onions | Transplant outdoors (spring) | Mar 22 – Apr 20 |
| Broccoli | Start seeds indoors (spring) | Feb 15 – Mar 21 |
| Broccoli | Transplant outdoors (spring) | Mar 22 – Apr 20 |
| Broccoli | Start seeds indoors (fall) | Jul 1 – Jul 11 |
| Broccoli | Transplant outdoors (fall) | Jul 31 – Aug 11 |
| Cabbage | Start seeds indoors (spring) | Feb 5 – Mar 5 |
| Cabbage | Transplant outdoors (spring) | Mar 5 – Apr 5 |
| Cabbage | Start seeds indoors (fall) | Jun 21 – Jul 21 |
| Cabbage | Transplant outdoors (fall) | Jul 21 – Aug 21 |
| Leaf lettuce | Sow outdoors (spring) | Mar 5 – May 21 |
| Leaf lettuce | Sow outdoors (fall) | Jul 21 – Sep 6 |
| Spinach | Sow outdoors (spring) | Feb 26 – Apr 11 |
| Spinach | Sow outdoors (fall) | Aug 7 – Sep 11 |
| Radishes | Sow outdoors (spring) | Mar 5 – Apr 25 |
| Radishes | Sow outdoors (fall) | Jul 21 – Sep 21 |
| Kale | Sow outdoors (spring) | Mar 22 – Apr 11 |
| Kale | Sow outdoors (fall) | Jul 14 – Aug 21 |
| Carrots | Sow outdoors (spring) | Apr 5 – May 21 |
| Carrots | Sow outdoors (fall) | Jun 21 – Aug 6 |
| Garlic | Plant outdoors (fall) | Oct 21 – Nov 21 |
Where these dates come from
ZIP code 65256 is matched to the NOAA station Columbia U Of M, MO, 22.3 km away, at 770 ft elevation (21 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Columbia U Of M, MO (used) | 770 ft | Apr 5 | Oct 31 |
| New Franklin 1W, MO | 641 ft | Apr 13 | Oct 22 |
| Boonville, MO | 752 ft | Apr 12 | Oct 25 |
| Boonville, MO | 744 ft | Apr 5 | Oct 29 |
Frost dates near Harrisburg
- Columbia, MO 65205 · last Apr 5, first Oct 31
- Sturgeon, MO 65284 · last Apr 13, first Oct 25
- Rocheport, MO 65279 · last Apr 5, first Oct 31
- Hallsville, MO 65255 · last Apr 5, first Oct 31
- Fayette, MO 65248 · last Apr 13, first Oct 22
- Clark, MO 65243 · last Apr 13, first Oct 25
- Higbee, MO 65257 · last Apr 13, first Oct 25
- Renick, MO 65278 · last Apr 13, first Oct 25
Frequently asked questions
- When is the last frost in Harrisburg, MO?
- For ZIP code 65256, the average last spring frost (32°F) is April 5, based on NOAA 1991-2020 climate normals for the Columbia U Of M, MO weather station. There is a 1-in-10 chance of a frost after April 21.
- When is the first frost in Harrisburg, MO?
- The average first fall frost (32°F) is October 31. There is a 1-in-10 chance of frost by October 17, so tender plants are at risk from that point on.
- How long is the growing season in 65256?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 207 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.