I'd bet the biggest hurdle you'll face is getting quality data.
I guess it depends on what you're looking for, but at least some weather/climate/earth-surface stuff can be grabbed right off the air from the various satellites. Some of that stuff is beamed down unencrypted and anybody with the right receiver setup (which can be as simple as an RTL SDR dongle, AFAIK) can grab the data and use it.
http://www.rtl-sdr.com/rtl-sdr-tutorial-receiving-noaa-weath...
http://noaasis.noaa.gov/NOAASIS/pubs/Users_Guide-Building_Re...
You can also download a lot of data here, although it presumably wouldn't be as timely as getting it direct from the satellite.
https://www.ncdc.noaa.gov/data-access/satellite-data/satelli...
https://arnesund.com/2015/05/31/using-amazon-machine-learnin...
Wouldn't a prediction with 80% accuracy still be enormously useful in most use cases?