Frost dates for 54246Washington Island, WI
The average last spring frost in Washington Island is May 15 and the average first fall frost is October 14, giving a typical growing season of about 152 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 15
- Average first fall frost
- Oct 14
- Growing season
- 152 days
Safer after May 31 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 200 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 13 · May 28 · Jun 10 | Sep 19 · Oct 2 · Oct 16 | 127 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 15 · May 31 | Sep 28 · Oct 14 · Oct 31 | 152 days | 100% |
| Hard freeze (28°F) | Apr 20 · May 3 · May 18 | Oct 10 · Oct 28 · Nov 10 | 176 days | 100% |
Planting calendar for Washington Island
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 14 – Jun 20 |
| Tomatoes | Transplant outdoors | May 31 – Jun 24 |
| Peppers | Start seeds indoors | Apr 14 – May 15 |
| Peppers | Transplant outdoors | Jun 14 – Jul 15 |
| Eggplant | Start seeds indoors | May 1 – May 30 |
| Eggplant | Transplant outdoors | Jun 14 – Jul 15 |
| Cucumbers | Sow outdoors | Jun 14 – Jul 4 |
| Summer squash | Sow outdoors | May 31 – Jul 15 |
| Winter squash & pumpkins | Sow outdoors | Jun 14 – Jul 15 |
| Snap beans | Sow outdoors | May 31 – Jul 27 |
| Sweet corn | Sow outdoors | May 31 – Jun 24 |
| Watermelon & cantaloupe | Sow outdoors | Jun 14 – Jul 15 |
| Okra | Sow outdoors | Jun 7 – Jun 30 |
| Peas | Sow outdoors (spring) | Apr 14 – May 30 |
| Potatoes | Plant outdoors (spring) | Apr 14 – Jun 14 |
| Onions | Start seeds indoors (spring) | Mar 3 – Mar 30 |
| Onions | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (spring) | Mar 27 – Apr 30 |
| Broccoli | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (fall) | Jun 14 – Jun 24 |
| Broccoli | Transplant outdoors (fall) | Jul 14 – Jul 25 |
| Cabbage | Start seeds indoors (spring) | Mar 17 – Apr 14 |
| Cabbage | Transplant outdoors (spring) | Apr 14 – May 15 |
| Cabbage | Start seeds indoors (fall) | Jun 4 – Jul 4 |
| Cabbage | Transplant outdoors (fall) | Jul 4 – Aug 4 |
| Leaf lettuce | Sow outdoors (spring) | Apr 14 – Jun 30 |
| Leaf lettuce | Sow outdoors (fall) | Jul 4 – Aug 20 |
| Spinach | Sow outdoors (spring) | Apr 7 – May 21 |
| Spinach | Sow outdoors (fall) | Jul 21 – Aug 25 |
| Radishes | Sow outdoors (spring) | Apr 14 – Jun 4 |
| Radishes | Sow outdoors (fall) | Jul 4 – Sep 4 |
| Kale | Sow outdoors (spring) | May 1 – May 21 |
| Kale | Sow outdoors (fall) | Jun 27 – Aug 4 |
| Carrots | Sow outdoors (spring) | May 15 – Jun 30 |
| Carrots | Sow outdoors (fall) | Jun 4 – Jul 20 |
| Garlic | Plant outdoors (fall) | Oct 4 – Nov 4 |
Where these dates come from
ZIP code 54246 is matched to the NOAA station Washington Is, WI, 1.8 km away, at 686 ft elevation (7 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Washington Is, WI (used) | 686 ft | May 15 | Oct 14 |
| Ephraim 1Ne-Wwtp, WI | 733 ft | May 14 | Oct 18 |
| Escanaba, MI | 590 ft | May 13 | Oct 7 |
| Cornell 5Se, MI | 794 ft | May 19 | Oct 1 |
Frost dates near Washington Island
- Ellison Bay, WI 54210 · last May 15, first Oct 14
- Sister Bay, WI 54234 · last May 14, first Oct 18
- Ephraim, WI 54211 · last May 14, first Oct 18
- Fish Creek, WI 54212 · last May 14, first Oct 18
- Baileys Harbor, WI 54202 · last May 8, first Oct 13
- Bark River, MI 49807 · last May 19, first Oct 1
- Escanaba, MI 49829 · last May 19, first Oct 1
- Wells, MI 49894 · last May 19, first Oct 1
Frequently asked questions
- When is the last frost in Washington Island, WI?
- For ZIP code 54246, the average last spring frost (32°F) is May 15, based on NOAA 1991-2020 climate normals for the Washington Is, WI weather station. There is a 1-in-10 chance of a frost after May 31.
- When is the first frost in Washington Island, WI?
- The average first fall frost (32°F) is October 14. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 54246?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 152 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.