Never Miss the Bloom Again

Our Mission

Cherry blossom season is one of the most magical times to visit Japan — but it is also one of the most fleeting. The bloom window for any given spot can be as short as 5–10 days, and peak bloom (満開) often shifts by days compared to official forecasts due to weather variations.

Travelers who rely solely on traditional apps or meteorological agency forecasts often arrive a few days too early or too late, walking through bare branches or already-fallen petals. We built JapanSakura.live to solve exactly this problem: giving you a real-time, ground-truth view of the bloom wherever you are planning to go.

How It Works

We aggregate multiple real-time data sources and process them with an AI-assisted analysis pipeline to produce a reliable bloom score for each spot. Our system is designed to be transparent, observable, and continuously improving.

The result is a Bloom Score for each spot that reflects how likely it is to be at peak right now, based on the combination of all available signals. Scores update automatically every 2–6 hours throughout the cherry blossom season.

Coverage: 8 Regions, 50+ Spots

We cover major cherry blossom viewing locations across Japan, spanning eight distinct regions from Hokkaido in the north to Kyushu and Shikoku in the south. Each region has its own dedicated hub page with region-specific spots and bloom data.

Data Freshness & Accuracy

Our pipeline runs automatically via GitHub Actions CI every 2–6 hours during cherry blossom season. Each run collects fresh social posts, re-evaluates bloom scores, and updates the HTML. You can see the "last updated" timestamp at the top of each regional hub page.

We are transparent about our uncertainty. Bloom scores are presented with confidence indicators, and we clearly distinguish between high-confidence (multiple recent posts confirming peak bloom) and low-confidence (limited or conflicting signals) assessments. We do not manufacture precision that does not exist in the underlying data.

Key data sources include:

• Threads public posts (searched by spot name + sakura keywords)
• X (Twitter) public search results
• Yahoo! Japan blog and news posts
• Bluesky public posts
• Official sakura forecasts from Japanese meteorological organizations
• Webcam streams from partner sources and YouTube

About the Creator

JapanSakura.live is an independent project built and maintained by Simon Hsu, a developer based in Taiwan. The project is open source and developed in public on GitHub.

Simon has a background in product engineering and a particular interest in building tools that aggregate messy, real-world signals into clear, actionable decisions. The cherry blossom tracker started as a personal frustration project after a trip to Tokyo in 2025, and grew into a full-stack system covering all of Japan.

The stack includes:

• Frontend: Static HTML with native JavaScript, Tailwind CSS, and Leaflet.js maps — no heavy frameworks
• Backend: Node.js scripts running as GitHub Actions CI jobs
• AI: LLM-assisted post classification with rule-based pre-filtering
• Hosting: Cloudflare Pages with R2 CDN for images and OG assets

The project is entirely self-funded. If you find it useful, sharing it with friends planning a Japan trip is the best way to support it.

Contact & Feedback

We welcome feedback, spot suggestions, webcam tips, and partnership inquiries. We are particularly interested in hearing from:

• Travelers who found the site useful (or found it to be inaccurate)
• Local residents near famous sakura spots who can provide ground-truth checks
• Travel agencies or media interested in data licensing or collaboration
• Webcam operators willing to feature their stream on the site

Email us at: [email protected]

Summary in Other Languages