What Can You Do at Tomamu in Summer?
Tomamu's summer headline act is the Unkai Terrace 'sea of clouds' — plus hiking, golf, an indoor beach and lavender day trips to nearby Furano.
Summer at Tomamu transforms the resort into Hokkaido's premier alpine playground, with the Unkai Terrace sea-of-clouds viewing deck, hiking, ziplining, mountain biking, the Mina Mina Beach indoor water park, and easy day trips to the Furano lavender fields and Biei rolling hills — a genuinely different holiday from the winter ski resort, and increasingly popular with travellers escaping summer heat further south.
The Unkai Terrace: Tomamu's signature attraction
The Unkai (Sea of Clouds) Terrace is the single most photographed feature of Tomamu and the activity most international visitors come specifically to experience. From mid-May through mid-October, the resort runs a dedicated gondola from 5am to allow guests to reach the summit observation deck at sunrise. On clear, humid mornings — typically 30-40% of days during the season — a sea of low cloud forms in the valleys below the summit, leaving you above an ocean of white with mountain peaks poking through. It's spectacular and unlike anything else in Asia.
The Unkai gondola runs to a purpose-built deck with multiple viewing platforms, a Cloud Walk suspended deck that appears to float above the clouds, hammocks, and a Cloud Pool — a giant net stretched across a valley that you can lie in. There's a small café serving coffee and breakfast pastries. The whole experience takes 90 minutes to two hours. The resort posts a forecast each evening predicting the next morning's cloud probability, so you can choose whether to set the alarm. Even on non-cloud days the summit views across Hokkaido are remarkable.
Hiking trails on Tomamu mountain
Once the snow has melted, the same lifts that serve skiers in winter access a network of well-maintained hiking trails ranging from 30-minute summit loops to 6-hour traverses. The most popular routes are the Tomamu Mountain summit loop (1 hour, easy to moderate, accessed by gondola) and the longer ridge traverse to Mount Tomamu (3-4 hours, moderate, with stunning panoramic views of central Hokkaido). Trail signage is in Japanese and English, and trail maps are free at the base.
Bear awareness is part of summer hiking in Hokkaido — you'll see warning signs at every trailhead and bear bells are commonly worn. Encounters are rare on the popular trails near the resort but always treat the wildlife seriously. Pack water, sunscreen, a light rain jacket, and proper hiking shoes (not running shoes — the trails get rocky in places). Mid-summer mornings are the best time to start; afternoon storms occasionally develop, especially in July and August.
Mina Mina Beach and water activities (open year-round)
Mina Mina Beach, the indoor wave pool described in our winter activities post, is open year-round. In summer it pairs perfectly with the genuinely warm outdoor weather — Hokkaido summers reach pleasant 25-28°C days — making for a full day of water-based fun without the contrast of snow outside. The outdoor water-play area opens from June through August with splash pools and water slides for younger children.
For more adventurous water options, several local operators run rafting trips on the Mukawa and Sorachi rivers, both within a 60-minute drive of Tomamu. River conditions are best from May (snowmelt-driven) through September. Half-day trips suit families with older children; gear and transfers are provided. Cycling around the resort and along easy local roads is also popular in summer, with bike rentals available at the base.
Adventure activities: ziplining, MTB and segway
Adventure Mountain — Tomamu's summer activity zone — runs a long zipline circuit through the forest canopy, with multiple stages at increasing height and length. It's suitable for ages 8 and up with an adult, and takes about 90 minutes to complete the full loop. The longest single section runs over 250 metres and is a properly fast ride; the views over the Hidaka mountains are stunning from the upper platforms.
Mountain biking is increasingly popular, with the resort running a small bike park accessed by gondola for downhill riders, plus a network of cross-country trails for less aggressive riding. Bike rental, helmets, and pads are all available; lessons are bookable for first-timers. Segway tours run on the gentler trails near the resort base for visitors who want to cover more ground than walking allows without the fitness demands of cycling. Most adventure activities require booking 24-48 hours ahead during the peak July-August weeks.
The Cloud Walk and Cloud Pool installations
Designed by the architectural team behind the Unkai Terrace expansion, the Cloud Walk is a curving cantilevered deck that extends out from the mountainside and appears to disappear into the clouds on misty mornings. Walk to the end and the perspective is genuinely vertiginous — the Cloud Walk is the photo backdrop you'll see on every Tomamu social media post. Best visited at sunrise alongside the Unkai experience.
The Cloud Pool is a large industrial net stretched across a valley off the side of the summit deck — you lie or sit in it as if you're floating on a cloud. It's safe, properly engineered, and the photo opportunities are endless. Both installations are accessed via the same gondola ticket as the Unkai Terrace, so visiting one usually means visiting both. Allow 60 minutes for the Cloud Walk and Cloud Pool combined, plus the morning Unkai experience itself.
Day trips: Furano lavender fields and Biei
The lavender fields of Furano peak in mid-July and are one of the most iconic landscapes in Japan during their short flowering window. From Tomamu, Furano is about a 90-minute drive — easy as a self-drive day or via a chartered van for groups. The Tomita Farm is the most famous stop, with multiple lavender varieties flowering across rolling hillsides, alongside other flower fields including poppies, salvia and lupins.
The Biei area, between Furano and Asahikawa, is the rolling-hills landscape that features in Hokkaido tourism photography year-round. The Patchwork Road and the Blue Pond are both must-see stops, easily combined with a Furano day trip. Bring camera gear; this area is one of Japan's most-photographed landscapes for good reason. A full Furano-Biei day trip from Tomamu is around 8-10 hours door to door, comfortable as a day trip but worth considering an overnight if your itinerary allows.
Golf at Tomamu Golf Course
The Tomamu Golf Course is an 18-hole championship course set within the resort grounds, designed to make full use of the surrounding mountain landscape. The course is consistently ranked among the better resort courses in Hokkaido, with well-maintained greens and dramatic elevation changes that produce memorable holes. Golf carts are provided and the course caters comfortably to international visitors.
Tee times can be booked through the resort or online up to several months ahead. Equipment rental is available for visitors who haven't brought clubs, and the pro shop stocks the essentials. A golf-and-Unkai-and-spa day combination is popular with travelling couples — sunrise at the summit, breakfast back at the resort, 18 holes through the morning, lunch at the clubhouse, and afternoon at the Mina Mina spa facilities.
When to visit Tomamu in summer
The summer season at Tomamu effectively runs from late May through mid-October. Each month has a different character. Late May and early June are quiet, green and lush as the snowmelt finishes — fewer activities are running but accommodation is at its cheapest and the trails are at their freshest. July is peak summer with the warmest days, full activity programme, and the Furano lavender at its best. August is busy with Japanese summer school holidays driving family bookings.
September and early October are arguably the sweetest months — comfortable temperatures, autumn colours starting in late September across the upper mountain, the Unkai Terrace at its most reliable thanks to seasonal humidity patterns, and far fewer crowds than summer peak. October requires warmer evening clothing as nights drop close to freezing at altitude. The Unkai Terrace closes for the season in mid-October as winter operations preparations begin, so plan your dates around the published seasonal calendar each year.
A sample summer day at Tomamu
4:30am alarm, dressed and at the Unkai gondola by 5am, on the summit by 5:30 watching the sun rise above the cloud sea. Coffee at the summit café, photos at the Cloud Walk, an hour relaxing in the Cloud Pool. Down by 9am for a proper breakfast back at the apartment. Mid-morning hike on the Mountain Centre loop until lunch. Afternoon split — kids to Mina Mina, adults to the spa or golf course or just a good book on the deck. Family dinner at one of the Hotalu Street restaurants, in bed by 10 ready to sleep through the next morning's sunrise.
Summer at Tomamu is a quieter, slower-paced experience than winter — there's no urgency to be on the first lift. It suits travellers who want mountain scenery, fresh air, and a calm rhythm. Reach out with your dates and group composition and we'll help you put together the right mix of activities, day trips and rest days for a properly memorable summer week in central Hokkaido.