Do you know if weatherspark used public or private data sources? I've been working on some open source data visualization tools and if the data sets were public perhaps we could build something with weather data sets in mind.
After WeatherSpark shut down I spent a few minutes poking around weather data sources before getting overwhelmed and giving up. It looks like they get all their historical data from Weather.gov. (WeatherSpark lists their data sources here: https://weatherspark.com/about ...and weather.gov appears to have their data available for download from NOAA:
https://www.ncdc.noaa.gov/)