The short answer
April for cherry blossoms · November for autumn leaves.
Tokyo's two great windows are about 4-5 weeks each. Outside those, the city is perfectly visitable, but expect either summer heat (July-September) or winter cold (December-February).
Best month-by-month for Tokyo
- March-April: cherry blossoms peak around April 1-7. Book hotels 6+ months ahead.
- May: warm, dry, post-Golden Week (after May 5) is calmer than April.
- June: rainy season starts. Not ideal — but Hydrangea bloom in temple gardens.
- July-August: hot, humid, festival-heavy (Sumida fireworks, Obon). Hokkaido is the cool escape.
- September: typhoon season risk. Late September can be lovely if storms cooperate.
- October-November: autumn leaves at Rikugien and Mt Takao. Dry, mild, photographically stunning.
- December: dry, illuminations everywhere, lower crowds — until New Year shutdown.
- January-February: cold but rarely snowy. Ski day-trips possible from Tokyo. Lowest tourist crowds.