I've no idea how it works in the US, but in Europe:
if you are outside controlled airspace you cannot get SVFR
If the weather station reports below VFR minimums you will have the evidence against you in case you prang.
If the weather station data is seriously and obviously duff, you need to bring it to someone's attention and have it taken offline/NOTAMed/etc., while it's fixed. In the meanwhile, the accuracy of your eyeball weather assessments will presumably be judged against regional weather data, and data from nearby stations. Again, mostly only if accident investigators need to get involved
So, I'm not really getting what it is that you're trying to ask, although I'm sure your question is not about whether it's sensible to fly in crap weather, which is what I've ended up answering. Perhaps you would care to rephrase your question a bit better? Also some background on your qualifications and level of experience would go a long way towards getting a decent answer.