I have a follow up question that is slightly related...
Currently, it's raining in Montreal. The API knows this because the JSON response has the "rain" icon in it. However, every metric related to precipitation is returning 0.0mm, except for the precip_1_hr_in which is -9999 (null).
My question is how can the API return the right icon but not the right amount of precipitation? I can confirm it's raining by simply looking outside the window.