2026 Prediction Competition

When will the cherry trees bloom in 2026?

We invite contestants to submit their predictions for Washington, D.C. (USA), Kyoto (Japan), Liestal-Weideli (Switzerland), Vancouver, BC (Canada) and New York City (USA), along with a compelling narrative and reproducible analysis containing any data and code used. Complete entries will be eligible to win prizes—based on multiple categories, including best prediction and best narrative. See the complete competition rules for details.

New in 2026: WSS ‘Petals and Probabilities’ hackathon

The Washington Statistical Society is hosting the hackathon ‘Petals and Probabilities,’ where students will work together to predict when the cherry trees will bloom this spring, followed by networking.

This in-person event will be hosted at Georgetown University’s 111 Massachusetts Avenue on February 21^st, 2026 from 9 AM to 4 PM. The featured lunch speaker is Scott Olesen, Lead Data Scientist at the Center for Forecasting and Outbreak Analytics in the Centers for Disease Control and Prevention. Free food will be provided, and monetary prizes will be awarded.

Interested students from undergraduate through PhD should bring a laptop and register at this link before the event: https://forms.gle/t6SwNcKUPJmf594A7. It is not necessary to participate in the hackathon to enter the competition. Lead organizers of the hackathon are Ujjayini Das and Patrick Roney. Sponsors include the Washington Statistical Society, the American Statistical Association, and the Massive Data Institute at Georgetown University.

Check out the entries of the past winners to get some inspirations on successful modeling techniques and narratives. The “getting started” videos provide information on cherry trees, bloom dates, and how to start modeling. In addition, see this template GitHub repository and the tutorial on the The Law of the Flowering Plants.

Please contact the competition organizers with any questions using the contact submission form.

Organizers

Judges