Last winter, Delavan Lake froze on January 20. The ice was off by March 10, which made 49 days of cover in total. Twelve years earlier, the winter of 2013–14 kept ice on the lake for 116 days, from December 16 to April 11.

The Delavan Lake Sanitary District has logged ice-on and ice-off dates for every winter since 1983–84. Read top to bottom, it shows the freeze has moved from December into January. That gives the lake a stretch between late October and first ice that used to run a few weeks and now often runs closer to two and a half months.

The Freeze Moved to January

The DLSD's historical ice coverage record covers 17 winters from 1983–84 through 1999–2000. In 13 of them, the lake's main freeze came in December. Only four froze in January.

The last seven winters went the other way.

Six of those seven freezes came in January. The one December freeze, in 2022, also produced the longest season of the group at 81 days. Compare a few winters from the early part of the record. In 1989–90 the ice came on December 7. In 1995–96 it came on December 16 and stayed 106 days. In 1983–84 it came on December 19 and stayed 107 days.

The district's rules for calling it are strict. A thin skin of ice that forms one morning and breaks up that afternoon doesn't count. Ice-off is called only once a boat can travel from any shore to the deepest part of the lake without hitting ice. That's why the log also shows short false starts in some winters. The lake froze on December 12, 2019 and opened again the next day, then froze for good on January 17. The 56 days in the table count only that main stretch. December still brings a first glaze some years. It just doesn't hold the way it used to.

The rest of this post is about the months that later freeze leaves open.

The Harvesters Clock Out First

Weed harvesting wraps up first. In its October 1, 2026 memo to the Town of Delavan Lake Committee, the Sanitary District said the harvesting crew was down to one or two operators, with the season ending "in a few weeks." The same memo noted that a new high-side dump truck had arrived and that the district would test BioBase sonar for tracking weed density.

There's no 2026 season total yet, so last year remains the benchmark. In 2025, harvesters worked 77 days and removed a record 10,259 cubic yards of plants from about 302 acres. The memo also shows a wet fall. September brought 5.56 inches of rain and two runoff events, which put the year-to-date total at 36.17 inches.

When the last harvester comes off the water this fall, the log says first ice is most likely still two months or more away.

The Launch Switches to Winter Hours This Sunday

On November 1, the Town of Delavan boat launch moves from its April 1–October 31 schedule to winter hours, which run through March 31. Delavan Lake Community Park, at 1220 South Shore Drive on the corner of Highway 50, closes for the winter. The town still welcomes ice fishing there, but the gatehouse isn't staffed in the off-season.

This year brought one change at the launch. Under the 2026 boat launch update, daily and seasonal passes now go through a cashless automated system, bought at the machines on site. With nobody at the gatehouse after Sunday, those machines are the only way to buy a pass.

Taken with the ice log, the calendar works out like this. The park goes into winter mode on November 1. In most recent years, the lake has stayed open water well into January after that.

Open Water Through the End of Musky Season

Late fall is when this year's fish stocking pays off for anglers. The Delavan Lake Improvement Association reported that the Wisconsin DNR stocked more than 20,000 walleye in late August, then added 550 musky and 1,500 crappie in mid-September. The DLIA said a lake-wide fish survey is planned for 2027, and that those fish were the only additions allowed until the survey is done.

Delavan Lake has its own rules under the DNR's 2026–27 regulations for the lake:

• Walleye, sauger and hybrids: 18-inch minimum, three daily, season open May 2, 2026 to March 7, 2027
• Largemouth and smallmouth bass: 18-inch minimum, one daily, same season, with catch and release open year-round
• Northern pike: 32-inch minimum, one daily, same season
• Muskellunge and hybrids: 40-inch minimum, one daily, season May 2 to December 31, 2026 on open water
• Panfish: open all year, no minimum length, 25 daily

The musky line is where the ice log matters. The open-water musky season closes December 31. In six of the last seven winters, the lake was still open on that date. In the December-freeze years of the 1980s and 1990s, ice often formed before the season's last weeks. Lately, the musky season has tended to run its full length on open water.

This is general information drawn from the DNR's published table, not legal advice. Rules can change, so check the DNR page itself before you head out.

For gear, Lakeside Bait & Tackle at 3542 State Road 50 keeps cold-season hours from October 1 through April 30, open 6 a.m. to 6 p.m. every day. The shop's guide page lists Halligan Outdoors for ice-fishing trips and Reddy Guide Service, which guides on Delavan and Geneva lakes in all four seasons.

When Ice Arrives, the Calendar Is Already Running

Lake Lawn Resort's winter season starts well before the lake freezes. Its cold-weather page lists holiday events from Thanksgiving through Valentine's Day, including light displays, cookie decorating and visits from Santa. Once the lake is frozen, it adds ice skating on Delavan Lake, with an indoor pool for days when the ice isn't ready. The resort's dining page lists the Lookout Bar & Eatery with a Friday fish fry and live music on Saturdays.

Then there's Winterfest. Delavan Friends of the Park has asked people to save the date for January 16, 2027, and no program has been posted yet. Last year's Winterfest took place on January 17, 2026 at Delavan Lake Community Park. The town's park events page lists vintage snowmobiles, ice carvings, local high school bands and the Wisconsin Marching Band. According to the district's count, the lake froze three days after that festival, on January 20.

Over the last seven winters, the main freeze has fallen between January 7 and January 21 in every year but one. The January 16, 2027 Winterfest date sits right inside that window. On the record so far, the festival could land on new ice or on a lake that is still open.

At The JH Collective, we follow Delavan Lake through the whole year, from launch hours to the ice log. If you're thinking about what your lakefront property is worth as the seasons change, we'd be glad to talk it through. Request a Complimentary Market Review & Private Consultation.