Weatherspark has some great visualizations of historical weather by time of day, e.g.: http://weatherspark.com/history/29735/2014/Seattle-Washington-United-Sta

Weatherspark has some great visualizations of historical weather by time of day, e.g.: http://weatherspark.com/history/29735/2014/Seattle-Washington-United-States http://weatherspark.com/history/29735/2014/Seattle-Washingto... Unfortunately they don't have a great way to compare cities, aside from just loading multiple pages and eyeballing.