[danso]

For climate data, the U.S. NOAA is probably the go-to stop:

http://www.ncdc.noaa.gov/cdo-web/

I know lots of other data sources, but don't feel it's worth your while for me to list them...just because data exists somewhere doesn't mean that it's easy to understand and/or easy to publish...but I can point you to a couple of places where you can talk to others and get advice on it:

The OpenData StackExchange: http://opendata.stackexchange.com/

And the datasets subreddit: http://reddit.com/r/datasets

And of course, there is the visualization subreddit: http://www.reddit.com/r/dataisbeautiful