The last several times I've been there right in time for cherry blossom season (end of March beginning of April) and it's completely lovely. The weather can be a bit chilly but there have been enough warm and sunny days for a pleasant stay. It's also great to see all of the friends and families getting together for cherry blossom viewing.
This time I'm going in October, a few days from now and it looks like it will be too hot and rainy for my comfort. I can't figure out if it's sudden massive downpour, consistent heavy fall, on and off light fall or just mildly raining all day. I'm sure I'll still enjoy myself but it will be harder to pre-plan day trips from Tokyo to outdoor areas like Nikko or Kamakura. I didn't think October was supposed to be quite as rainy as it is right now.
