Frost dates for 54827Cornucopia, WI
The average last spring frost in Cornucopia is May 20 and the average first fall frost is October 9, giving a typical growing season of about 140 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Oct 9
- Growing season
- 140 days
Safer after Jun 3 (1-in-10 risk)
Possible by Sep 25 (1-in-10 risk)
Last frost typically in 205 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 20 · Jun 1 · Jun 13 | Sep 17 · Sep 29 · Oct 11 | 118 days | 100% |
| Frost / freeze (32°F) | May 5 · May 20 · Jun 3 | Sep 25 · Oct 9 · Oct 23 | 140 days | 100% |
| Hard freeze (28°F) | Apr 24 · May 6 · May 21 | Oct 6 · Oct 23 · Nov 4 | 166 days | 100% |
Planting calendar for Cornucopia
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 19 |
| 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 29 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jul 22 |
| Sweet corn | Sow outdoors | Jun 5 – Jun 19 |
| 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) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 54827 is matched to the NOAA station Madeline Island, WI, 26.1 km away, at 660 ft elevation (245 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Madeline Island, WI (used) | 660 ft | May 20 | Oct 9 |
| Bayfield Fish Hatchery, WI | 615 ft | May 23 | Oct 2 |
| Bayfield 6 N, WI | 820 ft | May 20 | Oct 8 |
| Port Wing, WI | 651 ft | May 31 | Oct 2 |
Frost dates near Cornucopia
- Herbster, WI 54844 · last May 31, first Oct 2
- Bayfield, WI 54814 · last May 20, first Oct 9
- Washburn, WI 54891 · last May 20, first Oct 2
- Port Wing, WI 54865 · last May 31, first Oct 2
- Benoit, WI 54816 · last May 23, first Sep 29
- La Pointe, WI 54850 · last May 20, first Oct 9
- Iron River, WI 54847 · last May 24, first Sep 26
- Ashland, WI 54806 · last May 20, first Oct 2
Frequently asked questions
- When is the last frost in Cornucopia, WI?
- For ZIP code 54827, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Madeline Island, WI weather station. There is a 1-in-10 chance of a frost after June 3.
- When is the first frost in Cornucopia, WI?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 25, so tender plants are at risk from that point on.
- How long is the growing season in 54827?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 140 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.