 This study examined the seasonality of six common infectious diseases in tropical Australia over a 21-year period. It found that myliuidosis and leptospirosis were most prevalent in the wet season, while stephalococcal infections occurred throughout the year. Reketzial and cryptococcal infections were more likely to occur in cooler, drier months, while influenza was inter-seasonal. Climate did not significantly change during this timeframe, but the incidents of myliuidosis and reketzial disease increased substantially, suggesting that other factors such as socioeconomic status and urban development could play a larger role than climate in determining the incidence of these infections. In order to effectively manage these diseases, public health strategies should focus on addressing these underlying causes. This article was authored by Leigh J. Fairhead, Simon Smith, Beatricee Sim, and others.