Japan's Summer Festivals Are Shifting Dates Because of Record Heat in 2026 -- What Travelers Should Know

Japan's weather agency issued heat stroke alerts across most of the country in the week of July 20, 2026, forecasting back-to-back "kokushobi" -- a new heat category the agency introduced this year for days that hit 40°C (104°F) or higher. More than 100,000 people were hospitalized for heatstroke over the 2025 summer season, and the toll has been climbing again in 2026.

One quiet but very real effect: a growing list of Japan's best-known summer festivals and fireworks displays are no longer held in the hottest weeks of summer. If you're planning a trip around a festival you remember from a guidebook or a past visit, it's worth double-checking the current date -- some have moved by two months or more.

Festivals that have already moved

• Saga: Sakae no Kuni Matsuri. Traditionally an early-August event, the city moved it to late May starting in 2025 after 14 attendees were treated for heatstroke in 2024. The 2026 edition (its 55th) ran May 23-24 with zero reported heatstroke cases and roughly 278,000 visitors -- the second-highest turnout on record.
• Tokyo: Adachi Fireworks. Long held in late July, the display moved to late May starting in 2025 specifically to reduce heat-related risk; organizers say the change eliminated the dozen-plus heatstroke reports typical of the old July date.
• Yamagata: Sakata Fireworks. Held in August through 2024, the show moved to mid-September starting in 2025 after the riverbed venue flooded in a past heavy-rain year -- both heat and flood risk factored into the change.
• Chiba: Kashiwa Matsuri. One of the Kanto region's largest street festivals (roughly 700,000-800,000 visitors a year) moves from its traditional late-July weekend to September 19-20, 2026, for the first time. See our Kashiwa Matsuri 2026 guide for full details.
• Hiroshima: Minato Yume Hanabi. The city announced on July 22, 2026 that this fireworks display -- held every July since 2003 -- will move to September starting in 2027. That makes the July 25, 2026 show its last-ever July edition; see our Hiroshima Minato Yume Hanabi 2026 guide if you want to catch it before the switch.
• Oita: Nakatsu Hanakasaboko Matsuri. Known locally as "the festival with Japan's longest walking parade" (traditionally 30-40 km of flower-decorated floats), the city kept its 2026 dates but shortened the route and stationed paramedics along the course as a heat-safety measure instead.

What this means if you're planning a trip

Older travel guides, and even some festival listings, can lag behind these changes -- a festival you researched months ago may no longer be on the date you expect. A few habits help:

• Check the festival's own official site or social account within a week or two of your trip, not just a travel guide, since dates and even hours can shift.
• Expect more evening starts. Several rescheduled events -- and some that stayed on their original dates -- have pushed opening times later in the day to avoid peak-heat hours.
• Watch for a heatstroke alert (熱中症警戒アラート) on the day. These are issued by prefecture and can affect crowd flow, first-aid staffing, or last-minute timing tweaks even at events that didn't change their calendar date.
• Hydrate and plan shade breaks. Bring water, and expect organizers to add cooling mist stations, extra first-aid tents, or shortened routes, especially at daytime events.

For general advice on attending any Japanese festival, see our how-to-attend guide.