Frost dates for 54564Tripoli, WI
The average last spring frost in Tripoli is May 13 and the average first fall frost is October 3, giving a typical growing season of about 141 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 13
- Average first fall frost
- Oct 3
- Growing season
- 141 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 16 (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 11 · May 26 · Jun 6 | Sep 3 · Sep 21 · Oct 5 | 117 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 13 · May 27 | Sep 16 · Oct 3 · Oct 16 | 141 days | 100% |
| Hard freeze (28°F) | Apr 19 · May 2 · May 18 | Oct 1 · Oct 15 · Oct 29 | 165 days | 100% |
Planting calendar for Tripoli
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 12 – Jun 18 |
| Tomatoes | Transplant outdoors | May 29 – Jun 13 |
| Peppers | Start seeds indoors | Apr 12 – May 13 |
| Peppers | Transplant outdoors | Jun 12 – Jul 13 |
| Eggplant | Start seeds indoors | Apr 29 – May 28 |
| Eggplant | Transplant outdoors | Jun 12 – Jul 13 |
| Cucumbers | Sow outdoors | Jun 12 – Jun 23 |
| Summer squash | Sow outdoors | May 29 – Jul 13 |
| Winter squash & pumpkins | Sow outdoors | Jun 12 – Jul 13 |
| Snap beans | Sow outdoors | May 29 – Jul 16 |
| Sweet corn | Sow outdoors | May 29 – Jun 13 |
| Watermelon & cantaloupe | Sow outdoors | Jun 12 – Jul 13 |
| Okra | Sow outdoors | Jun 5 – Jun 28 |
| Peas | Sow outdoors (spring) | Apr 12 – May 28 |
| Potatoes | Plant outdoors (spring) | Apr 12 – Jun 12 |
| Onions | Start seeds indoors (spring) | Mar 1 – Mar 28 |
| Onions | Transplant outdoors (spring) | Apr 29 – May 28 |
| Broccoli | Start seeds indoors (spring) | Mar 25 – Apr 28 |
| Broccoli | Transplant outdoors (spring) | Apr 29 – May 28 |
| Broccoli | Start seeds indoors (fall) | Jun 3 – Jun 13 |
| Broccoli | Transplant outdoors (fall) | Jul 3 – Jul 14 |
| Cabbage | Start seeds indoors (spring) | Mar 15 – Apr 12 |
| Cabbage | Transplant outdoors (spring) | Apr 12 – May 13 |
| Cabbage | Start seeds indoors (fall) | May 24 – Jun 23 |
| Cabbage | Transplant outdoors (fall) | Jun 23 – Jul 24 |
| Leaf lettuce | Sow outdoors (spring) | Apr 12 – Jun 28 |
| Leaf lettuce | Sow outdoors (fall) | Jun 23 – Aug 9 |
| Spinach | Sow outdoors (spring) | Apr 5 – May 19 |
| Spinach | Sow outdoors (fall) | Jul 10 – Aug 14 |
| Radishes | Sow outdoors (spring) | Apr 12 – Jun 2 |
| Radishes | Sow outdoors (fall) | Jun 23 – Aug 24 |
| Kale | Sow outdoors (spring) | Apr 29 – May 19 |
| Kale | Sow outdoors (fall) | Jun 16 – Jul 24 |
| Carrots | Sow outdoors (spring) | May 13 – Jun 28 |
| Carrots | Sow outdoors (fall) | May 24 – Jul 9 |
| Garlic | Plant outdoors (fall) | Sep 23 – Oct 24 |
Where these dates come from
ZIP code 54564 is matched to the NOAA station Willow Rsvr, WI, 17.7 km away, at 1,532 ft elevation (33 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Willow Rsvr, WI (used) | 1,532 ft | May 13 | Oct 3 |
| Rice Rsvr Tomahawk-2, WI | 1,460 ft | May 10 | Oct 4 |
| Prentice #2, WI | 1,540 ft | May 23 | Sep 23 |
| Minocqua, WI | 1,601 ft | May 23 | Sep 27 |
Frost dates near Tripoli
- Brantwood, WI 54513 · last May 23, first Sep 23
- Heafford Junction, WI 54532 · last May 10, first Oct 4
- Tomahawk, WI 54487 · last May 10, first Oct 4
- Prentice, WI 54556 · last May 23, first Sep 23
- Ogema, WI 54459 · last May 23, first Sep 23
- Harshaw, WI 54529 · last May 26, first Sep 23
- Hazelhurst, WI 54531 · last May 23, first Sep 27
- Rib Lake, WI 54470 · last May 11, first Oct 1
Frequently asked questions
- When is the last frost in Tripoli, WI?
- For ZIP code 54564, the average last spring frost (32°F) is May 13, based on NOAA 1991-2020 climate normals for the Willow Rsvr, WI weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Tripoli, WI?
- The average first fall frost (32°F) is October 3. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 54564?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 141 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.