For the past few days now I've been comparing the cloud base and the visibility layers to both what I'm seeing outside as well as the Aviation Weather's "Helicopter Emergency Medical Services Tool" page and the Windy information is DRAMATICALLY inaccurate. So far I've found the FAA's Aviation Weather page to be about 10x more accurate for clouds and visibility under 5000' MSL. It is amazing the number of times in Windy that I'll look at the Metar of an airport and it shows MVFR or IFR conditions, and yet the cloud base and/or the visibility layer do not show ANY clouds at all over that region. That is a sure sign right there that the Windy information is in-accurate.
Today, right now, Windy shows literally NO clouds over my home airport and vis is unlimited yet my home airport is currently MVFR and you can't even see the runway from the airport web cams (I think it's actually degrading to IFR since the Metar was released.) Counter this to the FAA Aviation site and it fully shows MVFR conditions for my entire area with splotches of IFR and LIFR nearby, which is accurate.
I'd encourage any pilot to compare what you are seeing on Windy to https://www.aviationweather.gov/hemst and see for yourself just how inaccurate Windy is for your flight needs. It was a real eye-opener to me!!!