As a suggestion for future enhancements, how about put a zoom/pan map of the globe down below the graph and map all the stations to that. A visual way to see what stations are where.

Nifty enhancements, sir! Something popped out at me about your contrast of summer months' tight temp ranges with winter months' wide temp ranges. Just guessing, there's more cloud cover (green house gas) during those summer months, less during winter months. Extrapolating logically, one might expect that an increase in greenhouse gas (water vapor) would lead to LESS EXTREME weather, totally the opposite of what the catastrophists are claiming. Of course, I'm not sure why anyone would think these alarmists were capable of logic...

Thanks!

This is a fantastic tool. It would further improve the trust and credibility of the tool if you posted information about the data sources. How/where did you get them, are these raw thermometer data, is there any adjustments in the data whatsoever?