Another one of those ideas I'm obviously not the only one to have.
I've been wondering how the weather forecast for a certain day varies over time (specifically, within the window of a standard five-day forecast), and what the accuracy of a forecast for N days into the future might be.
ForecastAdvisor offers something along those lines, albeit not as detailed as I would have wanted. And, of course, not for Sweden. But hey... I'll take what I can get. For now.
For example, look at the 5-day weather forecast for New York, New York. If you click the forecast for today, you'll see the variation over the last five days.
It's not as hot as I had hoped, but still kind of cool. (Oooh, meteorogical puns!!)
Add some graphs, include historical data of what the weather was like on a given day, add data for Sweden and clean up the UI and, and I just might strike this long-time entry from my list of "someone should...".
(It's a big list.)