Frost dates for 54891Washburn, WI
The average last spring frost in Washburn is May 20 and the average first fall frost is October 2, giving a typical growing season of about 133 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Oct 2
- Growing season
- 133 days
Safer after Jun 3 (1-in-10 risk)
Possible by Sep 19 (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 21 · Jun 2 · Jun 16 | Sep 5 · Sep 22 · Oct 4 | 111 days | 100% |
| Frost / freeze (32°F) | May 3 · May 20 · Jun 3 | Sep 19 · Oct 2 · Oct 15 | 133 days | 100% |
| Hard freeze (28°F) | Apr 22 · May 5 · May 21 | Sep 28 · Oct 12 · Oct 27 | 159 days | 100% |
Planting calendar for Washburn
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 12 |
| 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 22 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jul 15 |
| Sweet corn | Sow outdoors | Jun 5 – Jun 12 |
| 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 2 – Jun 12 |
| Broccoli | Transplant outdoors (fall) | Jul 2 – Jul 13 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | May 23 – Jun 22 |
| Cabbage | Transplant outdoors (fall) | Jun 22 – Jul 23 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | Jun 22 – Aug 8 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jul 9 – Aug 13 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | Jun 22 – Aug 23 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | Jun 15 – Jul 23 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | May 23 – Jul 8 |
| Garlic | Plant outdoors (fall) | Sep 22 – Oct 23 |
Where these dates come from
ZIP code 54891 is matched to the NOAA station Ashland 3S, WI, 14.3 km away, at 826 ft elevation (24 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ashland 3S, WI (used) | 826 ft | May 20 | Oct 2 |
| Bayfield Fish Hatchery, WI | 615 ft | May 23 | Oct 2 |
| Ashland Kennedy Mem Ap, WI | 826 ft | May 23 | Sep 29 |
| Madeline Island, WI | 660 ft | May 20 | Oct 9 |
Frost dates near Washburn
- Bayfield, WI 54814 · last May 20, first Oct 9
- Ashland, WI 54806 · last May 20, first Oct 2
- Cornucopia, WI 54827 · last May 20, first Oct 9
- Benoit, WI 54816 · last May 23, first Sep 29
- Odanah, WI 54861 · last May 20, first Oct 2
- Herbster, WI 54844 · last May 31, first Oct 2
- La Pointe, WI 54850 · last May 20, first Oct 9
- Marengo, WI 54855 · last May 23, first Sep 29
Frequently asked questions
- When is the last frost in Washburn, WI?
- For ZIP code 54891, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Ashland 3S, WI weather station. There is a 1-in-10 chance of a frost after June 3.
- When is the first frost in Washburn, WI?
- The average first fall frost (32°F) is October 2. There is a 1-in-10 chance of frost by September 19, so tender plants are at risk from that point on.
- How long is the growing season in 54891?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 133 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.