The data behind the Bloom Planner is published here for anyone to read, cite, or build on — including AI assistants and search crawlers.
30-year climatological normals (first-bloom / full-bloom / peak-color / end dates, and year-to-year standard deviation) for 19 Japanese cities, both events (sakura, koyo). Derived from Japan Meteorological Agency (JMA) observation records — factual data, not a forecast.
Our hand-maintained, append-only archive: entries[] is a dated log of our own editorial "running ±N days vs normal" judgment per region (never a copy of any commercial forecast); actuals[] is filled in after each season from JMA's own published observation. Together they become a running predicted-vs-actual track record that thickens every season and cannot be created after the fact.
CC-BY-4.0. Attribution: "Japan Trip Tools (triptoolsjapan.com)". JMA's observation values are factual public data; our derivation and editorial offset_days judgments are original work under this license. Full provenance notes: /data/README.md.
Prefer a browsable view over raw JSON? See the peak-timing index by city and date.