“When is the best time to visit Lake Toya?” If you ask Kamonoya—which runs 11 whole-house rentals around the lake—our answer is: “Plan your trip around an event, and your stay becomes that much more rewarding.” In this article we introduce the main events that colour a year at Lake Toya, season by season. All dates and details reflect typical past years and may change from year to year. Before you set off, always check each event’s official website for the latest information.

The star from spring to autumn: the Lake Toya Long-run Fireworks Festival (typically late April to end of October)

The event that best represents Lake Toya is the Long-run Fireworks Festival. For roughly half a year, typically from late April to the end of October, fireworks are launched from the lake every night from around 20:45 for about 20 minutes. Unlike a festival held on one specific day, you can see them whenever you stay during the season—that’s its greatest appeal. Not having to “book time off for the fireworks day” is a wonderful thing when planning a trip.

Because the fireworks are launched from a moving boat, they can be viewed from a wide stretch of the onsen town’s lakeside. On days with poor weather they may be cancelled. For tips on watching, see our detailed Lake Toya fireworks guide.

May: the Lake Toya Marathon (17 May in 2026)

The Lake Toya Marathon is a popular race run along the lakeside. In 2026 the full marathon, 10 km and 5 km categories will be held on Sunday 17 May. Lake Toya in the fresh green of early summer is one of the clearest-aired times of the year—a lovely season for runners and the families cheering them on alike. Details on the course, time limits and entry are gathered in our complete Lake Toya Marathon guide.

Lodging around the race dates tends to fill up early. If you’re taking part with fellow runners or family, a kitchen-equipped whole-house rental lets you manage your own pre-race meal. Toya INN-West (sleeps 9, from ¥25,000/night) and Toya House (sleeps 8, from ¥24,000/night) are in the centre of the onsen town, handy for a stroll through the town after the race too.

June: the Lake Toya Manga & Anime Festa (typically June)

Set against the early-summer onsen town is the Lake Toya Manga & Anime Festa (TMAF). In 2026 it runs Saturday 27 to Sunday 28 June, with the whole onsen town as its venue and both admission and parking free. It’s a festival unique to this time of year, where the worlds of popular manga and anime merge with the onsen town. For highlights and access, see our Lake Toya Manga & Anime Festa guide.

Summer: peak fireworks season plus lake activities

In summer, alongside the fireworks, the Lake Toya sightseeing boat’s cruise to Nakajima and strolls along the lakeside are at their most pleasant. A drive around the lake—taking in spots like the Silo Observatory and Lake Hill Farm (about 40 km around the lake, roughly an hour by car)—is another summery pleasure. At a rental with a barbecue, a summer evening of a BBQ in the garden flowing straight into the fireworks is hard to beat. Rentals set up for BBQ are introduced in our Lake Toya BBQ cottage feature.

August: the Lake Toya & Mount Yotei Foothills Triathlon (typically August)

At the height of summer, a triathlon is typically held at Lake Toya in August. The swim takes place in Lake Toya, while the bike and run wind through the towns and villages at the foot of Mount Yotei (Toyako, Sobetsu, Toyoura, Makkari, Rusutsu, Kimobetsu and Kyogoku), with recent fields of around 200–300 athletes. It’s a summery race along a course looking out over the lake and Mount Yotei. For dates and roadside cheering, see our Lake Toya triathlon guide.

Autumn: the final season of foliage and fireworks

October lets you enjoy autumn foliage and fireworks at the same time—a quietly recommended time of year for us locals. The Long-run fireworks typically continue to the end of October. This is the only season when you can savour “autumn leaves + onsen + fireworks” all at once. Mornings and evenings turn chilly, so please come dressed warmly.

October: Cospa (typically October, an indoor event)

A spin-off of the Manga & Anime Festa, Cospa is typically held in October. It’s a mainly indoor event with free admission. Paired with an autumn-foliage drive or the onsen, it’s an autumn event you can enjoy even on a rainy or chilly day. For details, see our Cospa guide.

Winter: illuminations and a lake of stillness (winter season)

In winter, the onsen town typically holds illuminations, where lights glow amid the snowy scenery for a magical atmosphere. It’s a night-time walk you can take only in winter, the lights shining crisp in the sub-zero air.

Lake Toya is a lakeside resort where you can enjoy onsen and illuminations even amid the snow, and it works as a ski base too—about 30 minutes by car to Rusutsu and about an hour to Niseko. For details, see our winter ski-base guide for Lake Toya. Cloud9 Toya (sleeps 11, from ¥27,000/night), where you spend your time by the flames of a wood fire, is a whole-house rental with a wood-burning stove, well suited to a cosy snow-viewing retreat.

Tips for planning a stay around events

During the fireworks season, so you’re in time for the fireworks whichever night you stay, we recommend dining early—or cooking for yourselves at your lodging. Every Kamonoya property has a full kitchen and is a private whole-house or whole-room rental, so you can build your meals freely around the event schedule. Compare the properties from our list of facilities. For where to buy ingredients and local food tips, see our Lake Toya food guide.

Booking directly through our official site is the best-value official rate, with no agency commission (best-rate guarantee). Check availability here.

FAQ

Q1. When are the Lake Toya fireworks held?

The Lake Toya Long-run Fireworks Festival is launched every night for about 20 minutes from around 20:45, typically from late April to the end of October. On days with poor weather it may be cancelled.

Q2. When is the Lake Toya Marathon?

In 2026 the full, 10 km and 5 km categories will be held on Sunday 17 May. Lodging fills up easily around the race, so we recommend booking early. For the course and time limits, see our complete Lake Toya Marathon guide.

Q3. Are there seasonal events besides the fireworks?

Yes. There’s the Lake Toya Marathon in May, the Manga & Anime Festa in June, the triathlon in August, Cospa in October, and the illuminations in winter—an event for every season. As dates change from year to year, please check each event’s information to match your travel plans.