Each country has different seasons according to the country's geography. Indonesia as a tropical country has only two seasons namely the rainy season and the dry season. Here will be described diseases that have to do with changing seasons. Diseases arising from seasonal changes outside the tropics are not included in this discussion.
 There are several infectious diseases that must be watched out for according to the dry season and rainy season and the transition between these seasons. In the rainy season certain areas often experience floods. Infectious diseases that often occur in this condition such as increased cases of leptospirosis, diarrhea, dengue fever and several skin infections.
 If a child has a fever and there are symptoms of jaundice in flood conditions, an examination  for leptospira infection should be carried out. Patients with fever who do not go down with the administration of fever and sometimes accompanied by redness on the face in the rainy season should be suspected of dengue infection. Patients with fever are accompanied by pale or decreased awareness in certain areas that endemic tracing events toward malaria will be very helpful.
 In the dry season some regions in Indonesia experience drought. The impact of drought and the difficulty of getting clean water will affect the incidence of infectious diseases. The incidence of acute diarrhea will increase in areas that do not yet have adequate clean water facilities. The frequent occurrence of fires in large areas during the dry season has an impact on the emergence of respiratory infections such as acute respiratory infections and pneumonia.