Well, that's a tough question. For me, if someone put a gun to my head and asked me: "When's the best time to visit Japan?" I'd easily say "winter" (and not because I hoped this psychopathic traveler / Tofugu reader holding a gun to my head would freeze to death). No, I truly think winter's the best time to visit Japan, but that's because I like winter a lot. But, there are many things to take into account for when you visit Japan, and everyone has their own priorities. I'm hoping this post will help you to choose the best time to visit Japan for you depending on what you like (or don't like).
The Wind, The Rain, & The Temperature
The thing about the weather is that it really depends on what you like and what you don't like, as an individual. For me when I'm planning a trip to Japan, if I'm traveling I'd prefer it not to rain. That being said, I don't mind if it's super cold, which is why I make most of my trips to Japan during the winter (very low rainfall, cold). Then again, other people might like a few extra degrees in the temperature column, but would be willing to risk a little extra rain. Luckily, there are graphs for that.
*Note: These graphs are for Tokyo. I figured that would be a good "average" / "where most people go anyways" sort of place to start. Visit the website cited above for more info on individual cities.
The top graph provides information on rainfall in Japan. The second has to do with temperature. As you may have noticed, in general, the lower the temperature the less rain. So, if you want less rain, you should travel to Japan in January or December (February isn't bad either).
So why does it rain a ton in September? Well, that's typhoon season. Why's it so rainy in June? Well, that's rainy season. These are things that you need to know when visiting. If you don't do your research, you could end up thinking it's nice and warm and dry in August only to find yourself stuck in your hotel room during a typhoon. That would be no fun.
These are just general recommendations, though. Let's get into the seasons more intimately.
Each season of Japan has its pros and its cons. It's just a matter of what your preference is. One funny thing many Japanese believe is that they're the only country with four distinct seasons. While I agree they have four distinct seasons, the "only Japan has them" part is probably just a bit of… well… plain lies. But, since they are fairly distinct, I thought it would be good to lay each season out for you so you can figure out which one seems like a good fit for you.
The spring season is okay in terms of both rain and warmth, that is until you hit the rainy season which tends to pop up at the end of spring in June. To me, April and May are fairly good times to visit, not just because of the weather but also because of cherry blossom viewing (big deal in Japan).
If you want to do cherry blossom viewing, you'll want to arrive in late March or early April. Depending on where you are it may be prime time to view them or not. It's a lot like a cherry blossom wave that sweeps from the southern part of the country north, so if you're showing up late just travel up towards Hokkaido and maybe you'll catch up. Their best viewing time doesn't last too long.
Spring also has Golden Week, aka "OMG WHY MY MANGA NO UPDATE???" week, which is April 29 – May 5. A lot of people travel during this time, so it's often good to avoid it if you can.
Besides this, though, you'll find mild weather… not too hot and not too cold, as well as not too much rain (unless you're there too late in the spring). It's not my favorite time to go to Japan, but not my least favorite. I'd say out of all the seasons it ranks 3 of 4, so at least one thing is worse for me personally.
You would think that summer is the best time ever to visit Japan. Right? Right??? Well, in terms of my own opinion, I'd have to respond "wrong." I mean, look at the dude above. If that didn't scare you away, maybe this will.
The thing about summer is that it's hot. Like, really hot. On top of that the humidity is pretty terrible too. If it's not raining tanuki and kitsune due to typhoons (September is mega typhoon season) the humidity will feel so thick that it might as well be. That being said, I'm talking about the lower elevations. That's pretty much all the big cities in Japan. Plus, the farther south you go the worse it gets.
Of course, you could visit the mountains during the summer (perfect temperature, lower humidity) as well as Hokkaido. In fact, the one saving grace about summer is Hokkaido. Go there during the summer, it's absolutely perfect. As long as you avoid any typhoons (they don't make it up that far north for the most part) the weather is comfortable, it doesn't rain too much, and did I mention it's basically perfect? Mmmmm, melons!
In terms of my personal ratings, though, summer ranks 4 out of 4 for me. Although it can be nice if you go to the right places, overall it's my least favorite time to be in Japan, though I'm a wuss when it comes to heat and humidity. One saving grace, perhaps, is that you can catch Obon1 in August. But yeugh. So hot and humid.
As soon as typhoon season is over (early Octoberish), Japan gets pretty nice again. Rainfall drops considerably and the temperature is still fairly warm. Although it can be a little tricky at times, arriving in mid-October is often pretty sweet timing. You get the warmth of Japan without as much rainfall (though there still may be some).
Possibly a little safer is November, though if you want any warmth make sure to do it in the early part. November is even less rainy, though it's a little colder. Notice a pattern here?
I think for a lot of people autumn is the way to go. If you don't like the cold and you don't like to rain, autumn is generally superior to the kind of similar spring season. Although this depends your location, autumn means cheaper flights as well. Autumn ranks 2 of 4 for me, meaning you can probably guess what's coming next…
Winter is totally my favorite. I love the cold and am very happy to not travel while it's raining. When you come to Japan in December or January, you're basically guaranteed an (almost) rain free existence, unless you get really unlucky. It is cold, though, so be sure to pack accordingly.
There are some times in winter that are better than others, though. A little before Christmas the kids get out for a winter holiday. You may not want to travel during this time (so get to Japan in early December for peaceful not-too-busy traveling). Also, New Years is a huge deal in Japan. This could be a good thing or a bad thing for you. If you want to participate in the festivities, head on over to a big temple and party like it's 1868 again. If you don't like all the hotels to be full and all the trains packed, avoid the New Years time. Pretty much everything is closed the few days after New Years too, so you have to take that into account. To me, I love it, but it's not for everyone.
Another big event is the Snow Festival in Hokkaido. This is a week of snow-related fun, but it's very crowded and very cold. Not for everyone, but definitely the kind of event that you should go to if you can!
Besides these times and places, traveling tends to be pretty slow. You'll find that many big tourist attractions aren't as busy as they normally are, and while this can be a great thing because you get the whole place to yourself, it can also mean there is less lodging available too (for example, on Cat Island you can go there in the winter and get the whole island to yourself but there's no place to stay).
And of course, if you're into winter sports (skiing, snowboarding, competitive snowball fighting) winter is pretty nice in Japan. I'm not into those kinds of things, but if you are it may make for a more interesting trip.
For me, Winter ranks number 1 out of 4. It won't be #1 for you, necessarily, but I think it's overall the best time to visit. Just don't get caught in a snowdrift and freeze to death while visiting Jesus' grave, okay?
When Will You Travel?
You definitely know yourself better than I know you. But, the above is how I feel about travel with a little bit of non-winter-bias thrown in to boot. All the seasons have their good points. Sometimes it's price, sometimes it's the festivals, and sometimes it's the weather. You'll have to decide what's the most important to you. No matter when you choose, though, I'm sure you'll have a great time. It's not like ~~a little~~ a lot of humidity will ruin a whole trip. Humidity has its good points, right?
A Japanese summer holiday based on Buddhist customs. The spirits of ancestors come to visit household altars. There are lots of festivals all over Japan during this time. ↩