As the Kentucky Mesonet observation network grows in size, the need for detailed quality assurance procedures grows as well. The first version of the quality assurance system has been operational since mid 2010. Many basic data problems have been isolated as a result. Redundant instrumentation aids in quality assurance by providing the ability to intercompare similar data points at the same plot. However, other regional and local effects must be accounted for. Procedures currently in development include spatial analysis, long term bias isolation, and an improved precipitation algorithm.