OK guys, mystery solved....
So, as I mentioned at the beginning of this thread 2 days ago, my station is very badly sited and in addition it is a very cheap, poor quality model. I am well aware of this, not much I can do about it and I use it primarily for testing purposes for my template.
The data is actually quite accurate at night and in the winter and overcast weather - however - as soon as the Sun shines on it, the temperature goes crazy, very often over 5 or even more degrees C above what it should be.
In the last few days, we had exactly weather like this - my station was showing way too high temperature during the day, definitely not accurate, same goes for humidity.
On the other hand, I do have relatively very stable connection and almost 0 gaps. However, just this Friday the batteries completely drained, this happens about once a year. Before I got access to the station to change it, it was offline for 3 hours.
Just this Saturday they introduced this goldstar feature and I mentioned this and said - lets wait till Tuesday... my station was NOT a goldstar station. Since then, my station has been measuring inaccurate temperature every day. And, today... after 5 days since that incident, I curiously looked at WU. You can see the result below...
Conclusion: Data Quality, as WU sees it, means "
station that reports consistently with no gaps in data, regardless of "what" it actually reports". If you have very good quality data and not that good connection (ie. occasional gaps), your station will not be viewed by WU as "good quality". If you buy a station for 10 bucks, have temperature going crazy as soon as the Sun shines on it, have inconsistent wind values etc etc... but good connection and no gaps in data, based on WU, your station is of good quality....
Make your own opinion about "quality of WU", I personally do not award it a "goldstar"