I often like to understand the climate of areas I’m thinking of visiting to get a feel for the best times of year to go. Of all the sites I’ve found so far WeatherSpark has the most informative data displays. At a glance you can tell when it’s rainiest/snowiest, when it’s most humid, etc. It also has a host of other information available (although for reasons unclear to me some locations offer more information than others).
Check it out!