Atmospheric corrosion is a time variant process that is strongly dependent on environmental conditions. Classification of the environmental severity and corresponding corrosivity of a location is helpful for materials selection, protection system specification, and long-term maintenance planning. Environmental severity has historically been classified into six categories (ISO 9223) that link the environment with estimated corrosion rates. This classification system, among others, is based on annual averages of mass loss measurements, which can be costly and time intensive, without the flexibility to easily add new materials or environments for different applications. To advance these classification systems, four challenges need to be addressed: 1) facilitating the addition of new materials and galvanic couples for aerospace alloys, 2) reducing the time and labor associated with classifying new environments, 3) accounting for seasonal variations and weather events, and 4) allowing local environments to classify a severity. Real-time monitoring devices can satisfy these needs. Therefore, the current work is focused on developing a new severity classification system for aerospace applications using continuous environment and corrosivity measurements. Data were accumulated from multiple sources using corrosion severity and environment monitoring devices deployed under multiple conditions. The measurement systems included electrochemical sensors for measuring aluminum alloy free corrosion, galvanic corrosion, and solution conductance as a function of time. Solution conductance is alloy independent and a local environment measurement of contaminants. These three independent measurements across a range of benign to severe climates were found to have strong power law correlations (R² = 0.9). Given these dependencies, all three parameters were used to establish a self-consistent environmental severity classification system, similar in severity categories to three existing classification systems. This framework allows for the rapid addition of aerospace-relevant materials and locations to the severity classification to help inform severity-based maintenance practices.