Frost dates for 53121Elkhorn, WI
The average last spring frost in Elkhorn is May 2 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 2
- Average first fall frost
- Oct 9
- Growing season
- 157 days
Safer after May 20 (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 · Jun 1 | Sep 16 · Sep 30 · Oct 12 | 134 days | 100% |
| Frost / freeze (32°F) | Apr 18 · May 2 · May 20 | Sep 25 · Oct 9 · Oct 24 | 157 days | 100% |
| Hard freeze (28°F) | Apr 6 · Apr 20 · May 6 | Oct 5 · Oct 22 · Nov 4 | 182 days | 100% |
Planting calendar for Elkhorn
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 1 – Jun 7 |
| Tomatoes | Transplant outdoors | May 18 – Jun 19 |
| Peppers | Start seeds indoors | Apr 1 – May 2 |
| Peppers | Transplant outdoors | Jun 1 – Jul 2 |
| Eggplant | Start seeds indoors | Apr 18 – May 17 |
| Eggplant | Transplant outdoors | Jun 1 – Jul 2 |
| Cucumbers | Sow outdoors | Jun 1 – Jun 29 |
| Summer squash | Sow outdoors | May 18 – Jul 2 |
| Winter squash & pumpkins | Sow outdoors | Jun 1 – Jul 2 |
| Snap beans | Sow outdoors | May 18 – Jul 22 |
| Sweet corn | Sow outdoors | May 18 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 1 – Jul 2 |
| Okra | Sow outdoors | May 25 – Jun 17 |
| Peas | Sow outdoors (spring) | Apr 1 – May 17 |
| Potatoes | Plant outdoors (spring) | Apr 1 – Jun 1 |
| Onions | Start seeds indoors (spring) | Feb 18 – Mar 17 |
| Onions | Transplant outdoors (spring) | Apr 18 – May 17 |
| Broccoli | Start seeds indoors (spring) | Mar 14 – Apr 17 |
| Broccoli | Transplant outdoors (spring) | Apr 18 – May 17 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 4 – Apr 1 |
| Cabbage | Transplant outdoors (spring) | Apr 1 – May 2 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 1 – Jun 17 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 25 – May 8 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 1 – May 22 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 18 – May 8 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 2 – Jun 17 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 53121 is matched to the NOAA station Whitewater, WI, 22.1 km away, at 875 ft elevation (70 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Whitewater, WI (used) | 875 ft | May 2 | Oct 9 |
| Delavan Wwtp, WI | 882 ft | Apr 28 | Oct 14 |
| Lake Geneva Wwtp, WI | 846 ft | Apr 25 | Oct 21 |
| Burlington, WI | 751 ft | May 5 | Oct 9 |
Frost dates near Elkhorn
- Delavan, WI 53115 · last Apr 28, first Oct 14
- Springfield, WI 53176 · last May 5, first Oct 9
- Williams Bay, WI 53191 · last Apr 30, first Oct 10
- Lake Geneva, WI 53147 · last Apr 25, first Oct 21
- East Troy, WI 53120 · last May 3, first Oct 9
- Lyons, WI 53148 · last May 5, first Oct 9
- Fontana, WI 53125 · last Apr 30, first Oct 10
- Walworth, WI 53184 · last Apr 30, first Oct 10
Frequently asked questions
- When is the last frost in Elkhorn, WI?
- For ZIP code 53121, the average last spring frost (32°F) is May 2, based on NOAA 1991-2020 climate normals for the Whitewater, WI weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Elkhorn, 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 53121?
- 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.