Frost dates for 53120East Troy, WI
The average last spring frost in East Troy is May 3 and the average first fall frost is October 9, giving a typical growing season of about 157 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 3
- Average first fall frost
- Oct 9
- Growing season
- 157 days
Safer after May 21 (1-in-10 risk)
Possible by Sep 25 (1-in-10 risk)
Last frost typically in 182 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) | Apr 30 · May 16 · May 30 | Sep 17 · Sep 29 · Oct 13 | 137 days | 100% |
| Frost / freeze (32°F) | Apr 18 · May 3 · May 21 | Sep 25 · Oct 9 · Oct 25 | 157 days | 100% |
| Hard freeze (28°F) | Apr 7 · Apr 22 · May 7 | Oct 4 · Oct 22 · Nov 5 | 181 days | 100% |
Planting calendar for East Troy
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 2 – Jun 8 |
| Tomatoes | Transplant outdoors | May 19 – Jun 19 |
| Peppers | Start seeds indoors | Apr 2 – May 3 |
| Peppers | Transplant outdoors | Jun 2 – Jul 3 |
| Eggplant | Start seeds indoors | Apr 19 – May 18 |
| Eggplant | Transplant outdoors | Jun 2 – Jul 3 |
| Cucumbers | Sow outdoors | Jun 2 – Jun 29 |
| Summer squash | Sow outdoors | May 19 – Jul 3 |
| Winter squash & pumpkins | Sow outdoors | Jun 2 – Jul 3 |
| Snap beans | Sow outdoors | May 19 – Jul 22 |
| Sweet corn | Sow outdoors | May 19 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 2 – Jul 3 |
| Okra | Sow outdoors | May 26 – Jun 18 |
| Peas | Sow outdoors (spring) | Apr 2 – May 18 |
| Potatoes | Plant outdoors (spring) | Apr 2 – Jun 2 |
| Onions | Start seeds indoors (spring) | Feb 19 – Mar 18 |
| Onions | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (spring) | Mar 15 – Apr 18 |
| Broccoli | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 5 – Apr 2 |
| Cabbage | Transplant outdoors (spring) | Apr 2 – May 3 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 2 – Jun 18 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 26 – May 9 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 2 – May 23 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 19 – May 9 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 3 – Jun 18 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 53120 is matched to the NOAA station Sullivan 3Se, WI, 21.5 km away, at 933 ft elevation (77 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sullivan 3Se, WI (used) | 933 ft | May 3 | Oct 9 |
| Rochester Wwtp, WI | 783 ft | May 5 | Oct 10 |
| Burlington, WI | 751 ft | May 5 | Oct 9 |
| Lake Geneva Wwtp, WI | 846 ft | Apr 25 | Oct 21 |
Frost dates near East Troy
- Eagle, WI 53119 · last May 3, first Oct 9
- Mukwonago, WI 53149 · last May 1, first Oct 13
- Honey Creek, WI 53138 · last May 5, first Oct 9
- North Prairie, WI 53153 · last May 3, first Oct 9
- Elkhorn, WI 53121 · last May 2, first Oct 9
- Rochester, WI 53167 · last May 5, first Oct 9
- Palmyra, WI 53156 · last May 2, first Oct 9
- Genesee Depot, WI 53127 · last May 3, first Oct 9
Frequently asked questions
- When is the last frost in East Troy, WI?
- For ZIP code 53120, the average last spring frost (32°F) is May 3, based on NOAA 1991-2020 climate normals for the Sullivan 3Se, WI weather station. There is a 1-in-10 chance of a frost after May 21.
- When is the first frost in East Troy, WI?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 25, so tender plants are at risk from that point on.
- How long is the growing season in 53120?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 157 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.