Translation:We are running because it is raining.
It doesn’t work on mobile, here you are: http://www.thelocal.se/blogs/theswedishteacher/2012/04/16/for-for-att-darfor-att-and-eftersom/
This caused me some confusion until I saw that 'därför' = therefore and 'därför att' = because. I get the satisfaction that they're the same, and also the frustration that I cant think why 'att' should change the meaning in thay way.
I'm going to file it away with 'wherefore' as compound words that just mean what they mean.