Frost dates for 54439Hannibal, WI
The average last spring frost in Hannibal is May 20 and the average first fall frost is September 23, giving a typical growing season of about 125 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Sep 23
- Growing season
- 125 days
Safer after Jun 4 (1-in-10 risk)
Possible by Sep 6 (1-in-10 risk)
Last frost typically in 198 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) | May 17 · Jun 1 · Jun 19 | Aug 27 · Sep 13 · Sep 28 | 101 days | 100% |
| Frost / freeze (32°F) | May 3 · May 20 · Jun 4 | Sep 6 · Sep 23 · Oct 7 | 125 days | 100% |
| Hard freeze (28°F) | Apr 22 · May 6 · May 25 | Sep 16 · Oct 3 · Oct 18 | 147 days | 100% |
Planting calendar for Hannibal
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 | Apr 19 – Jun 25 |
| Tomatoes | Transplant outdoors | Jun 5 – Jun 3 |
| Peppers | Start seeds indoors | Apr 19 – May 20 |
| Peppers | Transplant outdoors | Jun 19 – Jul 20 |
| Eggplant | Start seeds indoors | May 6 – Jun 4 |
| Eggplant | Transplant outdoors | Jun 19 – Jul 20 |
| Cucumbers | Sow outdoors | Jun 19 – Jun 13 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jul 6 |
| Sweet corn | Sow outdoors | Jun 5 – Jun 3 |
| Watermelon & cantaloupe | Sow outdoors | Jun 19 – Jul 20 |
| Okra | Sow outdoors | Jun 12 – Jul 5 |
| Peas | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Potatoes | Plant outdoors (spring) | Apr 19 – Jun 19 |
| Onions | Start seeds indoors (spring) | Mar 8 – Apr 4 |
| Onions | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (spring) | Apr 1 – May 5 |
| Broccoli | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (fall) | May 24 – Jun 3 |
| Broccoli | Transplant outdoors (fall) | Jun 23 – Jul 4 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | May 14 – Jun 13 |
| Cabbage | Transplant outdoors (fall) | Jun 13 – Jul 14 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | Jun 13 – Jul 30 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jun 30 – Aug 4 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | Jun 13 – Aug 14 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | Jun 6 – Jul 14 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | May 14 – Jun 29 |
| Garlic | Plant outdoors (fall) | Sep 13 – Oct 14 |
Where these dates come from
ZIP code 54439 is matched to the NOAA station Jump Rvr 3E, WI, 11.3 km away, at 1,265 ft elevation (1 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Jump Rvr 3E, WI (used) | 1,265 ft | May 20 | Sep 23 |
| Holcombe, WI | 1,057 ft | May 5 | Oct 2 |
| Stanley Wwtp, WI | 1,080 ft | May 7 | Oct 3 |
| Ladysmith 3W, WI | 1,130 ft | May 27 | Sep 22 |
Frost dates near Hannibal
- Gilman, WI 54433 · last May 20, first Sep 23
- Jump River, WI 54434 · last May 20, first Sep 23
- Sheldon, WI 54766 · last May 20, first Sep 23
- Lublin, WI 54447 · last May 13, first Sep 26
- Conrath, WI 54731 · last May 5, first Oct 2
- Glen Flora, WI 54526 · last May 7, first Oct 3
- Holcombe, WI 54745 · last May 5, first Oct 2
- Tony, WI 54563 · last May 7, first Oct 3
Frequently asked questions
- When is the last frost in Hannibal, WI?
- For ZIP code 54439, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Jump Rvr 3E, WI weather station. There is a 1-in-10 chance of a frost after June 4.
- When is the first frost in Hannibal, WI?
- The average first fall frost (32°F) is September 23. There is a 1-in-10 chance of frost by September 6, so tender plants are at risk from that point on.
- How long is the growing season in 54439?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 125 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.