Weather APIs are among the most popular and the category has quadrupled over the past few years, with 47 weather APIs currently listed in the ProgrammableWeb API directory.
Popular weather data site Weather Underground (Wunderground) has a new version of its Weather Underground API and two things are notable: its former XML service is being phased out in favor of JSON. And it has a very clear pricing structure, though there's a free version for non-commercial projects.
Planet OS is excited to announce the launch of our first API designed specifically for geospatial and Earth observation data. The Planet OS API provides developers, researchers, and climate specialists with easy access to a growing catalog of Earth data from the world's most respected providers.