Influenza is not the only infectious disease with a season, according to an article on the Heelio website.
Seasonal drivers can affect the transmissions of acute infectious diseases like measles but also infections such as hepatitis B.
Four seasonal drivers can affect transmission dynamics: environmental factors, host behavior, host phenology and exogenous biotic factors.
Environmental factors can influence transmission through the effect of climate conditions, such as rain or temperature, on hosts and/or parasites. While the winter months are known for influenza season, March is the peak of varicella season in the U.S. and May through July is gonorrhea season.