Researchers know moisture plays a key role in weathering of many materials and often place moisture in a set of three primary weathering variables with sunlight and temperature. Researchers use southern Florida as a weathering reference environment because of its relative humidity, rain, condensation, and the important effect moisture plays in weathering. Researchers also make great efforts to include moisture variable control in artificial weathering tests for both simulation and acceleration of natural outdoor weathering degradation. Moisture represents an important focus for weathering studies, exposure standards, service life prediction methodology, and weathering device design. Several recent studies also show the important effect of moisture on material degradation rates and characteristics of automotive coating systems. Because of these historic and recent perspectives of moisture’s role in degradation of automotive coatings, a research goal was identified to perform a simple weathering experiment designed to help quantify the role of the moisture variable compared to other weathering variables on auto coating degradation.