Instead of having to re-type in the name of multiple towns every time a user revisits the site, allow users to save certain search criteria would save a lot of time. For example, if someone is always comparing data between America's 10 largest cities, those cities would only have to be typed in once and then saves in their search criteria so the next time they want to compare data between said cities, they would just need to search for a new set of data but the cities would already be there.