Current conditions and five-day forecasts? Every site has those. Historical data and averages dating back to the late 1940s, laid out in charts, graphs and averages? That's what Weatherspark is offering up to people looking for some context on their weather.
Text forecasts and numerical data from particular weather stations is laid out for you to scan and skip through. While Weatherspark provides the basic forecast given out by your local weather station (and shows you its location), it also provides its own kind of forecast, based on an average of this day in previous years. If you're wondering about year-to-year weather fluctuation, or just want to feel up or down about how rare today's weather is, you can easily lose yourself in this site. It's free to use, and it's still in beta, according to its creators.