Sometime in the next couple of years, I would like to make my first visit to Japan, as a tourist and/or language student. I think I’d go for a couple of weeks or (if I can swing it) a month.
In your opinion, what are the good/bad times of year to visit? I’d like to have decent weather (doesn’t have to be perfect, but I don’t want to be frozen, roasted, or soaked every day) and it would be nice if major cities aren’t empty of residents like Paris in August.
Thanks in advance,
E.
I forgot to mention that while I wouldn’t mind being there for an important holiday, festival, etc., I’m really more interested in just observing normal life, eating the food, learning about architecture, exploring cities & towns & countryside. I don’t need to be part of a tourist horde; just a tourist horde of 1.
Spring and autumn are definitely best – although winter isn’t too bad. Of course, it depends on what part of the country you are planning on, but I wouldn’t recommend summer for pretty much any part of Japan, except Hokkaido. It gets hellishly humid.
Winters, on the other hand, are cold, certainly, but very dry, and lots of clear blue skies, particularly in Tokyo or Kyoto. Autumn is my favorite season, personally, and I would recommend September, October, or maybe November. Spring is of course also beautiful (and if you’re lucky, you’ll get to see the cherry blossoms – around March/April), but it tends to be a bit grayer and rainier, in my opinion. And autumn has “momiji” – red leaves – which is just as beautiful as cherry blossoms. Kyoto will be extremely busy in the height of the red leaves season (and the cherry blossom season), but Kyoto is always busy.
The busiest times in Japan are the New Year and Obon (in early/mid August, when people go back to their homes to visit their families/ancestors) and Golden Week, which is in early May. There is also now a “Silver Week” in September. Both of these times are periods when there are numerous public holidays in a row, and the whole country goes on vacation. I wouldn’t recommend traveling then, if you enjoy your sanity and don’t want to get ripped off.
There are cool festivals all year round, in various parts of the country, so you should be able to find something no matter when you go.
For skiing, I found that winter was particularly good. 
When I visit, I always go in late September.
The university students are back in class which means the hostels are empty.
The weather is still warm, but visiting the northern parts of the country should be done first.
Cherry blossoms bloom from late March to late May, depending on what part of the country you go to. There are several famous and very beautiful places to see them. There are festivals to be found mostly any time, but a lot of them cluster in August. Too bad it’s so damn hot then, some of them are truly like nothing else.
Normal life observation is fine, and as someone mentioned, the best weather is fall/spring. But just remember that tourists horde for reasons, and not all of those reasons are stupid.
for Tokyo or nearby, I would definitely recommend April. The cherry blossoms are at their best, the weather is generally fine and it is not too hot yet. In any case, January/February is better than June/July since the winters are mild and the summers not. For other places, I don’t know.