Gunma’s festival calendar is anchored by a handful of genuinely distinctive events — Japan’s largest daruma fair, a marsh that turns white with skunk cabbage in early June, volcanic lake foliage in October — alongside the slower seasonal rhythms that make the prefecture rewarding to visit in any month. This guide covers the full year, with practical notes on timing, crowds, and access.
Winter (December to February)
Winter is one of Gunma’s most atmospheric seasons. Kusatsu Onsen reaches peak condition — the sulfuric water feels more restorative against cold air, the ski resort above town draws a steady crowd, and the Yubatake looks especially striking when steam rises in the freezing darkness.
Kusatsu Yubatake Illuminations (December to February)
Through the winter months, the Yubatake — Kusatsu’s central hot-spring field — is illuminated in the evenings. The combination of rising steam, the mineral-blue water, and coloured lights creates a scene that photographs well and draws visitors who might otherwise skip winter travel in Japan. The illuminations require no ticket; simply walk into the town centre.
Kusatsu Onsen Snow Festival (February)
Held in mid-February, the Kusatsu Snow Festival fills the area around the Yubatake with snow sculptures, open-air concerts, and outdoor food stalls. The festival typically spans two days on a weekend and is busy but manageable. Bus frequency from Takasaki increases on festival days; check the current schedule when planning travel.
Shorinzan Daruma Fair — Japan’s Largest (1 and 7 January)
The Shorinzan Darumaji Temple in Takasaki holds its annual Daruma Fair on 1 January and 7 January. With roughly 400,000 visitors across the two days combined, this is Japan’s largest daruma fair and one of the most important new-year rituals in the Kanto region. Vendors line the approach to the temple selling daruma dolls in every size, and many businesses and households come to purchase a new daruma for the year ahead.
If you are visiting on 1 January, expect very large crowds from mid-morning onward. The 7 January fair is slightly less crowded. Accommodation in Takasaki fills well in advance; booking at least four to six weeks ahead is essential.
Ice Fishing on Mt. Akagi and Lake Haruna (January to February)
Both Lake Onuma on Mt. Akagi and Lake Haruna freeze during January and February, and ice fishing for wakasagi (smelt) is a popular activity on both lakes. Rented equipment, heated fishing tents, and immediate tempura cooking of the catch are standard. Lake Haruna in particular is well organised for tourist participation and requires no prior fishing experience.
Minakami Ice Climbing Events (February)
Minakami, Gunma’s adventure-sports hub on the upper Tone River, hosts a small winter programme of ice climbing events in February. The area around the Tanigawa mountain range produces impressive ice formations in cold winters, and guided climbing sessions are available for beginners. Contact the Minakami Town tourism office for current scheduling.
Spring (March to May)
The Tone River thaws and starts running fast in March, marking the beginning of rafting season. Plum blossoms appear in lower Gunma before most of the rest of Kanto, and the mountains remain snow-capped well into April.
Tone River Rafting Season Opens (March)
The upper Tone River in Minakami produces consistent Class III to IV rapids when snowmelt is highest, typically from mid-March through May. Several outfitters operate from Minakami Station on the JR Joetsu Line, offering half-day and full-day guided raft trips. Prices run approximately ¥5,000–¥8,000 per person for a half-day. Wetsuits and equipment are provided; no experience is necessary. Spring is considered the best season for rafting due to high water volume and scenic snowmelt conditions.
Tomioka Silk Fair (May)
Held in May, the Tomioka Silk Fair celebrates the UNESCO World Heritage Site’s legacy with craft markets, traditional weaving demonstrations, and local food stalls around the mill grounds. Admission to the mill is ¥1,000 as standard; fair events are generally free or low-cost. This is a good time to visit Tomioka if you want a livelier atmosphere than usual.
Ikaho Stone Steps Festival (May)
The Ikaho Stone Steps Festival in May features traditional music, dance performances, and market stalls along the 365-step approach to Ikaho Shrine. The event brings a festive atmosphere to a town that is normally quiet and unhurried. Accommodation at Ikaho ryokan fills on the festival weekend; weekday visits in the same period offer the best of the spring weather without the crowds.
Cherry Blossoms in Lower Gunma (Late March to Early April)
The river valleys of lower Gunma — particularly around Takasaki and along the Watarase and Tone rivers — see cherry blossoms in late March to early April, slightly ahead of Tokyo. The Shorinzan Darumaji Temple grounds and Takasaki Park are both popular blossom-viewing locations. Temperatures can still drop sharply at night; bring a warm layer for evening walks.
Summer (June to August)
Summer in Gunma centres on Oze National Park, mountain hiking, and the summer festival season in Maebashi. The mountain areas stay 5–10 degrees cooler than Tokyo throughout July and August.
Oze National Park Opens — Skunk Cabbage Peak (Early June)
Oze’s boardwalk across the high-altitude marsh officially opens in late May or early June, depending on snowmelt. The opening week coincides with the peak of the mizubasho (Asian skunk cabbage) bloom: large white spathes rise from the waterlogged marsh floor across an area of roughly 800 hectares. The effect, with mist often still sitting low over the boardwalk in the morning, is remarkable.
Early June is Oze’s most photographed period and also one of its busiest. The main Hatomachi trailhead bus from Numata is packed on weekends; aim for a Tuesday to Thursday visit if your schedule allows. The boardwalk circuit is 9 kilometres and accessible to most fitness levels.
Netsu-no-Yu Summer Show at Kusatsu (June to August)
The Netsu-no-Yu bathhouse in Kusatsu — the main venue for the traditional yumomi (hot-water stirring) performance — runs shows throughout the summer months, typically several times daily. Performers use long wooden paddles to cool the spring water while singing traditional songs. The show is brief (about 30 minutes), informative, and included in the bathhouse entrance fee. This is one of the most distinctive cultural experiences available at any onsen town in Japan.
Maebashi Fireworks Festival (August)
Held in August along the Tone River near Maebashi, Gunma’s prefectural capital, this fireworks event is one of the largest in the region. Tens of thousands of spectators line the riverbanks, and the combination of the wide river and flat terrain means the fireworks are visible from a large area. Maebashi is about 30 minutes from Takasaki on the JR Ryomo Line.
Autumn (September to November)
Autumn transforms Gunma’s volcanic landscapes with some of the most intense foliage in the Kanto region. Mt. Akagi, Oze, and the Watarase Valley are the three main focal points.
Mt. Akagi Autumn Foliage (October)
The caldera lake of Mt. Akagi (Lake Onuma) is surrounded by forest that turns deep red and orange in October. The Akagi Shrine, set at the lakeside beneath the coloured canopy, makes for an atmospheric walk. A drive or bus ride to the summit road offers panoramic views of the foliage with the Kanto Plain visible far below. Peak colour is typically the second or third week of October at this elevation.
Oze Boardwalk Autumn Season (October)
The same boardwalk that draws visitors for spring skunk cabbage becomes a foliage destination in autumn. The grasses of the Oze marsh turn gold and amber while the surrounding forest goes red, and the contrast with the wooden boardwalk and open sky is visually striking. October is Oze’s second busiest period after early June; the same advice applies regarding weekday visits to avoid peak crowds.
Tomioka Silk Festival (October)
An autumn edition of Tomioka’s festival season, typically held in mid-October, features additional weaving demonstrations, artisan markets in the old merchant street, and evening events at the mill. Combine with a walk through the autumn-coloured town for a full day’s itinerary.
Haruna Shrine Autumn Festival (November)
Haruna Shrine, dramatically set against volcanic cliffs on the southern shore of Lake Haruna, holds its main autumn festival in November. The surrounding forest peaks in colour in late October to early November, and the combination of the shrine architecture and autumn leaves makes this one of Gunma’s most visually rewarding short excursions. Access is by bus from Shibukawa Station or by rental car.
Watarase Valley Autumn Foliage (November)
The Watarase Keikoku scenic railway, running through the valley on Gunma’s southeastern border, is one of the Kanto region’s most celebrated autumn foliage train routes. The line operates tourist trains (additional fare required) in November specifically for leaf-viewing. Check the railway’s official schedule for operating dates; the season typically runs for three to four weeks.
Practical Tips
Accommodation during the Daruma Fair: Takasaki hotels fill entirely for the nights of 31 December and 6 January. If you cannot secure Takasaki accommodation, Maebashi (15 minutes by train) is a workable alternative.
Oze peak-season crowds: Weekends in early June and mid-October regularly reach visitor capacity at the main trailheads. If you must visit on a weekend, take the earliest bus from Numata (departing around 6 am) to be on the boardwalk before the main crowd arrives.
Kusatsu ski season: The ski resort above Kusatsu typically opens in December and runs through late March. Book Kusatsu accommodation at least three to four weeks ahead for any Friday or Saturday during this period.
General access: All main festival locations are reachable by public transport from Takasaki, with highway bus connections from Shinjuku for Kusatsu and Minakami.