I would like to add some more to the site, but I am not sure what people want to see. Any ideas of suggestions would be greatly appreciated!
Disclaimer: I've never searched for weather-related information before, as the weather is practically the same all year round where I live :-)
But like any business, you need to match supply to customer demand. For a website, demand is the keywords / phrases that people are actually typing into Google and the other search engines.
There are many ways to get your hands on such data. Start from Google's free keywords tool: https://adwords.google.com/select/KeywordToolExternal