The openweathermap documentation clearly and explicitly say

If you do not see some of the parameters in your API response it means that these weather phenomena are just not happened for the time of measurement for the city or location chosen. Only really measured or calculated data is displayed in API response

That's well and fine but if I'm developing this now and want to be able to read about snow in a few months, how am I supposed to know all of the parameters? Is there an example of the a complete json object with all of the possible attributes so that I can develop against it now instead of brushing it up every time there's a new weather event?