Frost dates for 54517Clam Lake, WI
The average last spring frost in Clam Lake is May 16 and the average first fall frost is September 30, giving a typical growing season of about 136 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 30
- Growing season
- 136 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 17 (1-in-10 risk)
Last frost typically in 201 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 15 · May 27 · Jun 8 | Sep 7 · Sep 20 · Oct 2 | 116 days | 100% |
| Frost / freeze (32°F) | May 1 · May 16 · May 27 | Sep 17 · Sep 30 · Oct 12 | 136 days | 100% |
| Hard freeze (28°F) | Apr 20 · May 3 · May 18 | Sep 27 · Oct 10 · Oct 24 | 157 days | 100% |
Planting calendar for Clam Lake
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – Jun 10 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 20 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jul 13 |
| Sweet corn | Sow outdoors | Jun 1 – Jun 10 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 31 – Jun 10 |
| Broccoli | Transplant outdoors (fall) | Jun 30 – Jul 11 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 21 – Jun 20 |
| Cabbage | Transplant outdoors (fall) | Jun 20 – Jul 21 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 20 – Aug 6 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jul 7 – Aug 11 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 20 – Aug 21 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | Jun 13 – Jul 21 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 21 – Jul 6 |
| Garlic | Plant outdoors (fall) | Sep 20 – Oct 21 |
Where these dates come from
ZIP code 54517 is matched to the NOAA station Clam Lake 4W, WI, 6.1 km away, at 1,498 ft elevation (71 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Clam Lake 4W, WI (used) | 1,498 ft | May 16 | Sep 30 |
| Mellen 4 Ne, WI | 1,300 ft | May 26 | Sep 27 |
| Drummond, WI | 1,340 ft | May 20 | Oct 1 |
| Butternut 3Sw, WI | 1,570 ft | May 22 | Sep 24 |
Frost dates near Clam Lake
- Mellen, WI 54546 · last May 26, first Sep 27
- Glidden, WI 54527 · last May 22, first Sep 24
- Cable, WI 54821 · last May 20, first Oct 1
- Grand View, WI 54839 · last May 20, first Oct 1
- High Bridge, WI 54846 · last May 26, first Sep 27
- Marengo, WI 54855 · last May 23, first Sep 29
- Drummond, WI 54832 · last May 20, first Oct 1
- Mason, WI 54856 · last May 23, first Sep 29
Frequently asked questions
- When is the last frost in Clam Lake, WI?
- For ZIP code 54517, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Clam Lake 4W, WI weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Clam Lake, WI?
- The average first fall frost (32°F) is September 30. There is a 1-in-10 chance of frost by September 17, so tender plants are at risk from that point on.
- How long is the growing season in 54517?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 136 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.