Frost dates for 54452Merrill, WI
The average last spring frost in Merrill is May 11 and the average first fall frost is September 30, giving a typical growing season of about 139 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 11
- Average first fall frost
- Sep 30
- Growing season
- 139 days
Safer after May 27 (1-in-10 risk)
Possible by Sep 17 (1-in-10 risk)
Last frost typically in 196 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 24 · Jun 6 | Sep 5 · Sep 20 · Oct 3 | 118 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 11 · May 27 | Sep 17 · Sep 30 · Oct 12 | 139 days | 100% |
| Hard freeze (28°F) | Apr 19 · May 2 · May 16 | Sep 26 · Oct 10 · Oct 25 | 160 days | 100% |
Planting calendar for Merrill
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 10 – Jun 16 |
| Tomatoes | Transplant outdoors | May 27 – Jun 10 |
| Peppers | Start seeds indoors | Apr 10 – May 11 |
| Peppers | Transplant outdoors | Jun 10 – Jul 11 |
| Eggplant | Start seeds indoors | Apr 27 – May 26 |
| Eggplant | Transplant outdoors | Jun 10 – Jul 11 |
| Cucumbers | Sow outdoors | Jun 10 – Jun 20 |
| Summer squash | Sow outdoors | May 27 – Jul 11 |
| Winter squash & pumpkins | Sow outdoors | Jun 10 – Jul 11 |
| Snap beans | Sow outdoors | May 27 – Jul 13 |
| Sweet corn | Sow outdoors | May 27 – Jun 10 |
| Watermelon & cantaloupe | Sow outdoors | Jun 10 – Jul 11 |
| Okra | Sow outdoors | Jun 3 – Jun 26 |
| Peas | Sow outdoors (spring) | Apr 10 – May 26 |
| Potatoes | Plant outdoors (spring) | Apr 10 – Jun 10 |
| Onions | Start seeds indoors (spring) | Feb 27 – Mar 26 |
| Onions | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (spring) | Mar 23 – Apr 26 |
| Broccoli | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (fall) | May 31 – Jun 10 |
| Broccoli | Transplant outdoors (fall) | Jun 30 – Jul 11 |
| Cabbage | Start seeds indoors (spring) | Mar 13 – Apr 10 |
| Cabbage | Transplant outdoors (spring) | Apr 10 – May 11 |
| Cabbage | Start seeds indoors (fall) | May 21 – Jun 20 |
| Cabbage | Transplant outdoors (fall) | Jun 20 – Jul 21 |
| Leaf lettuce | Sow outdoors (spring) | Apr 10 – Jun 26 |
| Leaf lettuce | Sow outdoors (fall) | Jun 20 – Aug 6 |
| Spinach | Sow outdoors (spring) | Apr 3 – May 17 |
| Spinach | Sow outdoors (fall) | Jul 7 – Aug 11 |
| Radishes | Sow outdoors (spring) | Apr 10 – May 31 |
| Radishes | Sow outdoors (fall) | Jun 20 – Aug 21 |
| Kale | Sow outdoors (spring) | Apr 27 – May 17 |
| Kale | Sow outdoors (fall) | Jun 13 – Jul 21 |
| Carrots | Sow outdoors (spring) | May 11 – Jun 26 |
| Carrots | Sow outdoors (fall) | May 21 – Jul 6 |
| Garlic | Plant outdoors (fall) | Sep 20 – Oct 21 |
Where these dates come from
ZIP code 54452 is matched to the NOAA station Merrill, WI, 2.3 km away, at 1,250 ft elevation (7 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Merrill, WI (used) | 1,250 ft | May 11 | Sep 30 |
| Wausau Dwtn Ap, WI | 1,181 ft | May 6 | Oct 4 |
| Rice Rsvr Tomahawk-2, WI | 1,460 ft | May 10 | Oct 4 |
| Antigo, WI | 1,519 ft | May 14 | Sep 30 |
Frost dates near Merrill
- Brokaw, WI 54417 · last May 6, first Oct 4
- Irma, WI 54442 · last May 10, first Oct 4
- Wausau, WI 54401 · last May 6, first Oct 4
- Gleason, WI 54435 · last May 22, first Sep 24
- Marathon, WI 54448 · last May 6, first Oct 4
- Schofield, WI 54476 · last May 6, first Oct 4
- Aniwa, WI 54408 · last May 6, first Oct 4
- Athens, WI 54411 · last May 11, first Oct 1
Frequently asked questions
- When is the last frost in Merrill, WI?
- For ZIP code 54452, the average last spring frost (32°F) is May 11, based on NOAA 1991-2020 climate normals for the Merrill, WI weather station. There is a 1-in-10 chance of a frost after May 27.
- When is the first frost in Merrill, 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 54452?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 139 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.