Method and sources

All figures on this site are counted by us from the Japan Tourism Agency's (観光庁) Overnight Travel Statistics Survey (宿泊旅行統計調査), confirmed full-year results.

• 2025: 002010340.xlsx, downloaded 29 September 2026. 2024: 001905499.xlsx, downloaded 3 October 2026, containing the corrections the agency published on 26 August 2025. Both are listed on the agency's statistics page.
• Guest nights: table 2 (第2表), monthly sheets, all lodging types. Total guest nights (column 1) and foreign guest nights (column 16).
• City-hotel occupancy: table 8 (第8表), city hotels (シティホテル), read directly from the table.
• "Foreign" means guests with no address in Japan; foreign residents count as domestic guests.
• Per day: each month's nights divided by its days (2024 was a leap year).
• Quietest month: the lowest per-day month; months within 3% of it are shown as tied, because the smallest lodgings are sampled rather than fully counted.
• Calendar shading: five equal steps between each prefecture's own lowest and highest month.
• Checks: the 47 prefectures sum to the national total within rounding (at most 40 nights in any month).
• Sampling error: the agency publishes standard error rates by prefecture and month (reference sheets 2 and 3 in the same file). For 2025, every total guest-night figure is below 30%, but a few foreign-visitor figures are higher: Niigata (May–November) and Fukui (March, June–September). Those months are outlined with a dashed line in the calendar and marked † in the tables. Treat them as approximate.
• Correction, 6 October 2026: an earlier version of this page said no figures used had a high sampling error. We had only checked the agency's asterisk marks, which appear in the nationality table, not in the prefecture tables.

Limits. Hotel nights, not people at sights; day-trippers are not counted. Whole prefectures, not towns. One year: 2025 included the Osaka Expo (13 April–13 October) and a Lunar New Year in late January. No weather, prices or events.

The newsletter explains each analysis in full: Japan Off-Peak on Substack. Site built 2026-10-06.