Due to very warm weather in February, the cherry blossom forecast has changed from the initial projection announced a month ago.
Now the Weathermap website is predicting the first bloom in Tokyo on March 17 with full bloom coming on March 25. The peak viewing window is expected to be from March 24 to the 31st.
The Weathernews website also has a similar prediction. In its latest forecast from March 4, the first bloom in Tokyo is projected on March 18 with full bloom on March 25.
Source (In Japanese only): https://weathernews.jp/news/202603/040056/images/?n=003
Some spots are already moving their event period forward, in view of the change in forecast.
The Inui Street within the Imperial Palace will open to the public from March 21st (Saturday) to the 29th (Sunday), a week earlier than the previous year.
The first week of April might be a bit late in downtown Tokyo, but there should be plenty of viewing opportunities in neighboring Kanagawa or Chiba Prefecture. For example, the full bloom in Yokohama is not expected until March 31st. The Odawara Castle should also look nice through the first weekend in April since it is always a few days behind Tokyo as well.