Just in case no one has seen this yet, Forecast.io is being rebranded as DarkSky. This means all services including their API’s will change! See more details here: http://blog.darksky.net/introducing-darksky-net/
No need to worry about their public API yet. Excerpt from their blog:
Current developers need not worry: while we’ve updated the URL interface from api.forecast.io to api.darksky.net, the old one will live on until at least the end of the year. There’s plenty of time to update your apps and services to point to the new site.
Need to have this changed before the year ends 
