Weather can be such a fickle bastard. A rainy forecasts turns good, a supposed great day becomes terrible. WHO KNOWS WHAT'S GOING TO HAPPEN. Still. I use weather reports to give me a general idea of the temperature. WT360 for iPhone let's me know the weather nearly a year into the future.
There's enough apps that tell you what the weather is right now or what it will be in the near future but WT360 thinks a little more long term. Of course there are hourly forecasts (95 hours out) and specific daily forecasts (15 days away) but the heart is the fun little weather prediction for what's going to happen 11 months from now (spoiler: January 22nd is going to snow and suck, May 26 looks promising).
Because I'm more concerned about what next months's weather might be than what my phone tells me what the weather is right now. Taking a trip during historically bad weather can ruin your vacation, hosting a party when it rains? No fun. WT360 can't be treated as gospel, obviously, but it's easy access to solid data. Oh, and the fact that it changes your background to the city you're in is swell.
Download this app for:
You can see the future!
Can't be 100% reliable