Frost dates for 53115Delavan, WI
The average last spring frost in Delavan is April 28 and the average first fall frost is October 14, giving a typical growing season of about 168 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 28
- Average first fall frost
- Oct 14
- Growing season
- 168 days
Safer after May 14 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 179 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 26 · May 10 · May 26 | Sep 20 · Oct 3 · Oct 15 | 145 days | 100% |
| Frost / freeze (32°F) | Apr 12 · Apr 28 · May 14 | Sep 28 · Oct 14 · Oct 26 | 168 days | 100% |
| Hard freeze (28°F) | Apr 2 · Apr 15 · May 1 | Oct 8 · Oct 25 · Nov 8 | 192 days | 100% |
Planting calendar for Delavan
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 | Mar 28 – Jun 3 |
| Tomatoes | Transplant outdoors | May 14 – Jun 24 |
| Peppers | Start seeds indoors | Mar 28 – Apr 28 |
| Peppers | Transplant outdoors | May 28 – Jun 28 |
| Eggplant | Start seeds indoors | Apr 14 – May 13 |
| Eggplant | Transplant outdoors | May 28 – Jun 28 |
| Cucumbers | Sow outdoors | May 28 – Jul 4 |
| Summer squash | Sow outdoors | May 14 – Jun 28 |
| Winter squash & pumpkins | Sow outdoors | May 28 – Jun 28 |
| Snap beans | Sow outdoors | May 14 – Jul 27 |
| Sweet corn | Sow outdoors | May 14 – Jun 24 |
| Watermelon & cantaloupe | Sow outdoors | May 28 – Jun 28 |
| Okra | Sow outdoors | May 21 – Jun 13 |
| Peas | Sow outdoors (spring) | Mar 28 – May 13 |
| Potatoes | Plant outdoors (spring) | Mar 28 – May 28 |
| Onions | Start seeds indoors (spring) | Feb 14 – Mar 13 |
| Onions | Transplant outdoors (spring) | Apr 14 – May 13 |
| Broccoli | Start seeds indoors (spring) | Mar 10 – Apr 13 |
| Broccoli | Transplant outdoors (spring) | Apr 14 – May 13 |
| Broccoli | Start seeds indoors (fall) | Jun 14 – Jun 24 |
| Broccoli | Transplant outdoors (fall) | Jul 14 – Jul 25 |
| Cabbage | Start seeds indoors (spring) | Feb 28 – Mar 28 |
| Cabbage | Transplant outdoors (spring) | Mar 28 – Apr 28 |
| Cabbage | Start seeds indoors (fall) | Jun 4 – Jul 4 |
| Cabbage | Transplant outdoors (fall) | Jul 4 – Aug 4 |
| Leaf lettuce | Sow outdoors (spring) | Mar 28 – Jun 13 |
| Leaf lettuce | Sow outdoors (fall) | Jul 4 – Aug 20 |
| Spinach | Sow outdoors (spring) | Mar 21 – May 4 |
| Spinach | Sow outdoors (fall) | Jul 21 – Aug 25 |
| Radishes | Sow outdoors (spring) | Mar 28 – May 18 |
| Radishes | Sow outdoors (fall) | Jul 4 – Sep 4 |
| Kale | Sow outdoors (spring) | Apr 14 – May 4 |
| Kale | Sow outdoors (fall) | Jun 27 – Aug 4 |
| Carrots | Sow outdoors (spring) | Apr 28 – Jun 13 |
| Carrots | Sow outdoors (fall) | Jun 4 – Jul 20 |
| Garlic | Plant outdoors (fall) | Oct 4 – Nov 4 |
Where these dates come from
ZIP code 53115 is matched to the NOAA station Delavan Wwtp, WI, 3.1 km away, at 882 ft elevation (63 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Delavan Wwtp, WI (used) | 882 ft | Apr 28 | Oct 14 |
| Lake Geneva Wwtp, WI | 846 ft | Apr 25 | Oct 21 |
| Clinton Wwtp, WI | 924 ft | Apr 30 | Oct 10 |
| Pell Lake, WI | 840 ft | Apr 30 | Oct 13 |
Frost dates near Delavan
- Williams Bay, WI 53191 · last Apr 30, first Oct 10
- Walworth, WI 53184 · last Apr 30, first Oct 10
- Fontana, WI 53125 · last Apr 30, first Oct 10
- Darien, WI 53114 · last Apr 30, first Oct 10
- Elkhorn, WI 53121 · last May 2, first Oct 9
- Sharon, WI 53585 · last Apr 30, first Oct 10
- Lake Geneva, WI 53147 · last Apr 25, first Oct 21
- Zenda, WI 53195 · last Apr 25, first Oct 21
Frequently asked questions
- When is the last frost in Delavan, WI?
- For ZIP code 53115, the average last spring frost (32°F) is April 28, based on NOAA 1991-2020 climate normals for the Delavan Wwtp, WI weather station. There is a 1-in-10 chance of a frost after May 14.
- When is the first frost in Delavan, WI?
- The average first fall frost (32°F) is October 14. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 53115?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 168 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.