Nagai City Balloon Festival and Shirato River Canola Flowers

Nagai City in Yamagata Prefecture is a "town of water" with thriving agriculture, where the Mogami River and the Okitama-no-gawa River flow. The flower event that represents Nagai is the "Nagai Ayame Festival," held at Nagai Ayame Park. In 2026 it ran from Wednesday, June 10 to Sunday, July 5, and hot-air balloon flight experiences were also held during the period. Check the Nagai City official website for the next dates.

Nagai City, a Town of Water

Nagai City is a "town of water" with a history of prospering on the river transport of the Mogami River. Waterways still run through the city and streetscapes of old merchant houses remain, so you can still sense the appearance of former days. It is an agricultural city blessed with abundant water and fertile land, where rice, soba and flower cultivation flourish. The "ayame" (Japanese irises) and "tsutsuji" (azaleas) that bloom in the city are especially famous, and the attraction here is a natural environment coloured by flowers through all four seasons.

Hot-Air Balloon Flight Experience and Nagai Ayame Park

During the Nagai Ayame Festival, a "balloon flight experience" is held in which hot-air balloons float in the clear early-morning sky. For 2026 it is announced for 7:00-9:00 at Nagai TBC Stadium, and evening sessions from 18:00 to 20:00 are also planned for Saturday, June 20 and Saturday, June 27 (reservations given priority in all cases). Hot-air balloons are greatly affected by weather conditions, and sessions are cancelled or changed in rain or strong wind. Be sure to check the dates, times and whether the event will go ahead in advance with the Nagai City Tourism Association (0238-88-5279).

Nagai Ayame Park, the stage for the festival, covers about 3.3 hectares, where several hundred varieties of flowers bloom in profusion. Above all, the varieties known as "Nagai Koshu" (Nagai old varieties), which can be seen only in this park, are a must-see.

A Treasure Called "Nagai Koshu"

According to the explanation by the Nagai City Tourism Association, "Nagai Koshu" were originally planted in Nagai Ayame Park and are varieties unique to Nagai, discovered and certified as rare varieties in 1962 by the hand of former chairman Hirao of the Japan Iris Society himself. They are said to be closer to the wild original species than the old Edo-lineage flowers; the petals are smaller but the stems are tall, and their neat, refined form, retaining the look of a wild flower that large-blossomed varieties lack, has captivated people. There are currently 34 Nagai Koshu varieties, 13 of which are designated natural monuments of Nagai City.

Walking through the park, next to a gorgeous large-blossomed horticultural variety a cluster suddenly appears, standing straight and tall with smaller, dignified flowers. That is the Nagai Koshu. Their value lies not in competing in showiness but in preserving exactly the form they had when they grew wild. If you have time, looking at the large-blossomed varieties first and then moving on to the koshu section makes the difference clear and is all the more interesting.

Photography Tips

Ayame and hanashobu irises have thin petals, and their expression changes greatly with how the light falls.

• 🕐 Time of day: The slanting light of early morning and evening is recommended. The petals become translucent and the gradations of purple and white come out beautifully. Direct light at midday easily blows out the highlights and tends to flatten the shadows of the flowers
• 💧 After rain: Hanashobu are flowers that suit rain well. Just after water droplets settle on them the colours come out deeper, making for a moist, atmospheric shot
• 📸 Composition: Rather than shooting the mass of flowers vaguely, the trick is to choose one plant as the star and tidy up the background. Opening the aperture to blur the flowers behind makes the star stand out. Placing the curve of a boardwalk or garden path diagonally in the frame creates depth
• 🎈 Combining with the balloons: The balloon flight experience is mainly held in the early morning. A composition with flowers in the foreground and a balloon floating behind is appealing, but the balloons use a separate venue (Nagai TBC Stadium), so they will not necessarily fit into the same frame. The sure approach is to split your time: balloons first, then Ayame Park

Flowers Through the Seasons - "The Town of Water, Greenery and Flowers"

Nagai City protects its flower spots as a whole community, and there are sights to see in seasons other than the ayame season too.

• Cherry blossoms (mid to late April): There are many famous old trees, such as the nationally designated natural monuments "Isazawa no Kubo-zakura" and "Kusaoka no Myojin-zakura," and every spring the "Okitama Sakura Corridor" is held so you can enjoy a cherry-blossom tour
• White azaleas (mid to late May): Shiro Tsutsuji Park, where about 3,000 plants bloom across a 6.3-hectare site. Only white Ryukyu-type azaleas are planted, and among them is a group of old trees around 750 years old called the "Shichibei tsutsuji." With a large fountain, a waterfall and a stream linking Matsuga-ike and Hyotan-ike ponds, it is a place of relaxation for residents and visitors alike
• Ayame (mid June to early July): The season of the Nagai Ayame Festival
• Autumn maples (late September to early November): The "Momiji Corridor," where you can enjoy the contrast between atmospheric buildings and the red and yellow of the maples

In addition, along the Mogami River footpath near Nagai Bridge there is a privately owned plum grove of about 60 varieties and 500 trees, where you can sit in the rest area and view them at leisure. "Hagi Park," which dates back to 1929 when Abe Rinzo obtained seedlings from Saitama and began laying out the garden, stands next to Unohana Onsen Hagi-no-yu. If you wish to visit, please speak to the front desk of "Hagien," which manages the park.

Best Season and Access

The best season is mid-June to early July, when the ayame are at their peak and the festival period overlaps. In early summer the "Shiro Tsutsuji Festival" is also held at Shiro Tsutsuji Park (Matsugaike Park) in the city, so you can enjoy a tour of the flower spots.

For access, get off at "Ayame Koen Station" on the Yamagata Railway Flower Nagai Line, about 2 minutes on foot. By car it is about 60 minutes from Yamagata Zao IC, and there is free parking for about 500 vehicles. True to its name, the Flower Nagai Line has flower spots dotted along it, and as a local line running through peaceful rural scenery the train journey itself is also enjoyable.

Practical Information

• Best season: The ayame at Nagai Ayame Park are at their best from mid-June to early July, overlapping with the festival period.
• Event period: In 2026 the "Nagai Ayame Festival" ran from Wednesday, June 10 to Sunday, July 5, with opening hours of 9:00-18:00 (until 20:30 on June 20 and 27). Check the Nagai City official website for the next dates.
• Admission: Adults 500 yen (400 yen for groups of 20 or more), children (elementary and junior high school students) 200 yen (100 yen for groups).
• Access: Get off at "Ayame Koen Station" on the Yamagata Railway Flower Nagai Line, about 2 minutes on foot. By car, about 60 minutes from Yamagata Zao IC.
• Parking: Free, about 500 spaces.
• Clothing and equipment: If you join the early-morning balloon flight experience, bring a jacket, as mornings are chilly even in June. The park is outdoors, so do not forget protection from sun and rain.

*[About the hot-air balloons / essential reading] The hot-air balloon flight experience is held only on limited dates and times during the "Nagai Ayame Festival" period. For 2026 it is announced for 7:00-9:00 at Nagai TBC Stadium, with evening sessions from 18:00 to 20:00 on Saturday, June 20 and Saturday, June 27, reservations given priority in all cases. Hot-air balloons are strongly affected by weather conditions such as rain and strong wind, and can be cancelled or changed even on the day. Be sure to check the dates, times and whether the event will go ahead in advance with the Nagai City Tourism Association (0238-88-5279). If you are travelling from far away for the balloons, we recommend planning your itinerary so that it still works even if they are cancelled.*

📚 Sources

Nagai City tourism portal site (Nagai City Tourism Association) "Events," Yamagata Prefecture official tourism site "Travel to Yamagata," Nagai Ayame Festival, Nagai City website

*The above is based on information published by each facility and local government. Hours and fees are subject to change, so please check official sources before visiting.*