An investigation of some unexpected frost day increases in Southern Australia

Abstract

Understanding changes in frost events is vital given their impacts on crops. This study examines monthly frost day trends in southern Australia, using Australian homogeneous temperature stations. Century-scale annual frost day trends show decreases consistent with expectations in a warming climate. The past 32 years however exhibit more complex and seemingly contradictory changes. At some locations increases in annual number of frost days are observed, while other locations show decreases more consistent with the longer term trend. Assessing monthly trends, we find a consistent increase in frost days at all stations in southeast Australia in late autumn (May). The trends are downwards during..