For the rest of 2026, nobody will be looking through the biggest telescope in Williams Bay. Yerkes Observatory says the Great Refractor is out of service in October and November for maintenance before a planned restoration. The observatory's regular 2026 night-sky tours and Open Houses are also sold out. Yerkes has filled the gap by turning the dome itself into the draw. The Candlelight Walk on Oct. 23 and 24 lets visitors stand under the unlit telescope by candlelight. Then, from Nov. 20, the same room hosts Frostlights, which Yerkes describes as the first holiday program in its 130-year history.
If you live a few blocks from 373 W. Geneva Street and haven't been inside in years, this winter is a good time to go. The catch is that both events are short and ticketed, and the second one has a firm cap on visitors.
A telescope out of service for the season
The instrument is officially named the Sharon and Charles Angell Historic Refractor. In an August announcement, Yerkes said "long-awaited maintenance in preparation for restoration" would happen in October and November, paid for by the Paul M. Angell Family Foundation. While the refractor was down, the observatory offered five nights of Exploring the Night Sky tours on its 24-inch reflector. If clouds rolled in, those evenings moved indoors to the vaults, which hold 180,000 glass astronomical images, and to the old darkrooms in the observatory's lower levels. According to the observatory's ticket page, those 2026 tours are now sold out, and Open House visitors are asked to check back for 2027.
Yerkes hasn't published a scope, cost or completion date for the restoration that follows. It also hasn't said whether the telescope will be usable once the maintenance ends. Neither of this season's public events includes viewing through the refractor.
The grounds keep their usual schedule. The arboretum and outdoor trails are open from sunrise to sunset with no ticket, apart from occasional closures. Getting inside the building requires an advance ticket to a scheduled tour or event, and tickets go on sale two months ahead. With the regular tours gone for the year, two events are left on the calendar.
Oct. 23 and 24: candlelight under a dark telescope
The Yerkes Candlelight Walk runs Friday, Oct. 23, and Saturday, Oct. 24, from 7 to 9:30 p.m. About 2,000 candles line the paths through the 50-acre Olmsted arboretum, with learning stations along the trails and inside the building. The walk doesn't include telescope viewing, but everyone can go inside to see the Great Refractor and its dome, and Yerkes says the big dome will be candlelit.
Since the refractor is between maintenance and restoration, this is likely the last chance in 2026 to see the dome in its usual state, lit only by candles, before it becomes a light-and-sound stage in November.
Practical details from the event page:
- Tickets are $15 for adults 19 and older and $10 for anyone 18 and under.
- Parking is only at Williams Bay High School, 500 W. Geneva Street. There's no parking at Yerkes, and a free shuttle runs continuously between the school and the observatory from 7 to 9:30 p.m.
- It's a drop-in, self-guided event with no guided tours. Arrive any time after 7 p.m. and stay until the last shuttle leaves at 9:30.
- The walk happens rain or shine, and tickets are good on either night if your plans change.
For neighbors, this means event parking on both nights is concentrated at the high school lot on Geneva Street.
Nov. 20 onward: Frostlights fills the 280,000-pound dome
A month after the candles go out, the dome becomes the center of something new. Here's how the observatory's Frostlights page describes it:
"Frostlights is the transformation of Yerkes into a winter galaxy of light and sound inside the architectural masterpiece and 280,000 lb. dome housing the world's largest lens telescope."
The centerpiece is a 20-minute light-and-sound show in the Great Refractor dome, set to original music by film-score composers. The visual design comes from Lightswitch, whose past work includes projects for Disney, Apple and the Morton Arboretum. The custom light fixtures were built by Upstaging, which produces lighting and shows for artists and institutions around the world. Yerkes says the show casts the 12,000-pound telescope tube and the building's masonry in a completely new light, even for people who have seen the dome many times.
The rest of the building is part of the experience too. The central floor has holiday shopping, treats, winter activities for families, and a custom-painted photo backdrop by artist Neal Aspinall. A beer and wine bar is surrounded by vintage winter memorabilia. In the Ann M. Drake Family Library, winter lighting surrounds a tribute to Edwin Frost, who directed Yerkes from 1905 to 1932. It's a fitting name for the season's show.
The Frostlights FAQ answers most planning questions:
- Time slots: Each ticket covers a 90-minute window, capped at 50 guests. The dome show starts at :15 and :45 past each hour, so a 4 p.m. ticket gets you a 4:15 or 4:45 show and the run of the building until 5:30.
- Prices: $30 for adults 18 and older, $17 for ages 5 to 17, and $4 for ages 4 and under. Everyone gets a seat in the dome.
- Temperature: The central floor is heated and the dome isn't, so bring a coat.
- Parking: Frostlights has limited on-site parking. Yerkes asks guests to arrive no more than 15 minutes before their slot.
- Gifting: Because capacity is limited, Yerkes isn't offering Frostlights gift certificates. If you want to give it as a present, you'll need to buy tickets for a specific slot.
The dome windows will be blacked out, so a 4 p.m. slot in late December looks the same as a later evening one. That makes an afternoon slot a reasonable option for families with young children.
Two ways inside, side by side
| Candlelight Walk | Frostlights | |
|---|---|---|
| Dates | Oct. 23–24, 2026 | 26 dates, Nov. 20, 2026, to Jan. 2, 2027 |
| Format | Drop-in, 7 to 9:30 p.m. | 90-minute timed slot, 50 guests |
| Adult ticket | $15, ages 19+ | $30, ages 18+ |
| Parking | Williams Bay High School, shuttle only | Limited, on-site |
| The refractor | Viewable by candlelight, no telescope use | Centerpiece of a 20-minute light show |
The 26 nights, and how they fall around the holidays
Yerkes gives the run as Nov. 20, 2026, to Jan. 2, 2027, but the show doesn't run every day in that span. The Visit Lake Geneva event listing lists these dates:
- November: 20, 21, 27, 28 and 29
- Early December: 3 through 6, and 10 through 13
- The week before Christmas: 17 through 23
- Between the holidays: 26 through 30
- January: 2
Christmas Eve, Christmas Day, New Year's Eve and New Year's Day aren't on the list. Nov. 27 is the Friday after Thanksgiving, which makes it a likely pick for anyone with family in town for the long weekend. Dec. 17 through 23 is the only full week of consecutive dates, so a visit fits easily into the last stretch of holiday errands. If you're planning around guests arriving for Christmas, Dec. 26 through 30 is the window. With 50 guests per slot, expect the evenings closest to the holidays to sell out first.
The rest of the Bay's calendar around those nights
The Yerkes dates fit into a full village calendar. The Village of Williams Bay calendar lists a Drum Circle Social at Kishwauketoe Nature Conservancy, 251 Elkhorn Road, on Friday, Oct. 30, from 6 to 8 p.m. Village trick-or-treating is Saturday, Oct. 31, from 4 to 7 p.m.
Through November and early December, Kishwauketoe holds volunteer seed-cleaning sessions on Wednesday mornings, Nov. 4, 11 and 18 and Dec. 2 and 9, from 10 a.m. to noon at the Lions Recreation Center. They're listed in the village's October–December newsletter. Down by the water, the Pier 290 FAQ says its lakeside igloo dining starts the day after Thanksgiving and runs through March. Frostlights also runs that day, so a Friday-after-Thanksgiving evening could include both. Check with each venue before you go.
Frostlights tickets are timed and capped at 50 guests per slot. If the observatory down the street is part of your holiday plans, book those first and fit the rest of the season around them.
Linda Tongé has lived on Geneva Lake for more than 50 years and has seen how its landmarks, Yerkes among them, shape what a winter here feels like. If you'd like to talk about life near the north shore of Geneva Lake, or what owning a home in Williams Bay looks like through the off-season, Linda Tongé would be glad to hear from you. Schedule a Consultation.
