Visualization of the data underlying climate research

We have put together a map/chart combo to visualize the data that underlies climate research. You can filter the stations based on several parameters, and get both a visualization as well as a computed rate-of-change.

Tool: http://weatherspark.com/#!climatetrends;ws=29939;ctum=0;cth=...

Additional info: http://weatherspark.com/climatetrends

Feedback most welcome!

(and yes, the data is quite hairy - as are the estimates)

(and yes, the site is still using flash - it will be HTML5 one day, just not today)

My goodness. I didn't know about WeatherSpark at all. This is amazing.

One question: when I'm viewing a chart, in the "Temperature" section, if I hover over one of the faint curves, I get a tooltip telling what it represents. But in "Precip. Type" I do not. Is this a bug? How do I tell what those faint curves mean?