Box jellyfish
In Australia (mainly northern; however, box jellyfish can live in subtropical waters as far south as Sydney, with "Carybdea marsupialis" being recorded as far south as Bermagui, Sapphire Coast) the highest risk period for the box jellyfish is between October and May, but stings and specimens have been reported all months of the year. Similarly, the highest risk conditions are those with calm water and a light, onshore breeze; however, stings and specimens have been reported in all conditions.
Medusozoa
Cubozoa is a group commonly known as box jellyfish, that occur in tropical and warm temperate seas. They have cube-shaped, transparent medusae and are heavily-armed with venomous nematocysts. Cubozoans have planula larvae, which settle and develop into sessile polyps, which subsequently metamorphose into sexual medusae, the oral end of each polyp changing into a medusa which separates and swims away.