You probably already know that most people in Japan hang out their laundry to dry. Drive or ride past apartment buildings on a sunny day and you'll see clothes, towels, blankets and futons hanging from bars and draped over the rail. And what could be better than to have the sun dry and naturally remove odors and stains from your items? It's a wonderful thing. Well, at least when you don't have the strong winter wind like here in Shizuoka attempting to throw your stuff over the ledge (I've gotten quite clever at coming up with ways to keep things from blowing off the balcony).
And you probably also know that you wouldn't hang clothes outside if it's raining or looks like it's going to rain.
But what if you could know how fast your clothes might dry on any given day?
There's a neat tool on various weather websites that determines a "laundry index" or 洗濯指数 (せんたくしすう, sentaku shisuu) - essentially it tells you if it's a good day for hanging out laundry or not and how quickly certain items will dry.
For this example I'm going to use tenki.jp, though you can find the laundry index on Yahoo and other sites as well (and they are all the same so I can't say one is better than another).
First, go to tenki.jp, and then click on 指数情報 (しすうじょうほう, shisuu jouhou - sort of like "index information"), as in the picture below. (There's actually a map of Japan in that blank gray box but it didn't show up in my screenshot for some reason.)
Next, choose 洗濯 (せんたく, sentaku, laundry).
Scroll down and choose your prefecture, and then on the page that follows, scroll past the map to choose your location in the prefecture you chose. (Such as by area; central, east, west, etc.)
And finally, you reach the info below. This screenshot is an example of the Chubu (central) area of Shizuoka prefecture, from earlier today. The upper left box indicates an index of 100 (the highest possible) with a brief note underneath explaining that drying jeans and thick items outside is OK, meaning that they will dry rather quickly (as opposed to a lower index).
On the right is tomorrow, Thursday, with an index of 90 indicating that things will dry pretty quickly, which includes bath towels.
Unfortunately there isn't a "key" with every index number listed (aside from the key underneath the two top images) - so I don't know what the explanations are for every number... but I do know some of the lower numbers say things like "you should dry indoors today," and some of the middle numbers say something like "synthetic fabrics will dry quickly." And, though this is probably obvious, the more "hanging shirts" there are, the higher the index, and the more likely your items will dry quickly outside.
So have at it if you'd like. I thought it was kind of fun, even if not that necessary. If you scroll underneath this part above there are actually a bunch of other "indexes" you can look at, such as amount of UV rays, whether you should carry an umbrella or not, if you'll be able to see the stars or not, how likely it is that you might catch a cold, etc. I found some of them to be amusing, so you may want to take a look.