For Your Geographers/Scientists: WeatherSpark.COM
Link: WeatherSpark | Interactive Weather Charts
WeatherSpark is a new type of weather website, with interactive weather graphs that allow you to pan and zoom through the entire history of any weather station on earth.
Get multiple forecasts for the current location, overlaid on records and averages to put it all in context.
We're still in beta, so please pardon any rough edges on the site or glitches in the data - weather stations sometimes report bogus values, and we're working to sort those out.
We currently have more than 4,000 weather stations, but are working to add more.
Data pane zoomed to show greater time-scale:
Site welcome information [quoted above] is a bit contradictory but the graphs look OK.