The Japan Meteorological Agency announced today that the blossoms have opened for the cherry tree that they regularly monitor at Tokyo's Yasukuni Shrine. This announcement comes five days earlier than 2024.
With warm weather expected through Friday, the blossoms should reach peak viewing mode within the next 5 days or so. Normally the peak condition lasts for around a week meaning the first weekend in April (5th and 6th) would be the rough deadline for enjoying them in central Tokyo.
Areas outside of the city center or in a higher altitude will have a schedule that is behind by a few days.