Beach fungus (pityriasis versicolor) is a harmless skin disease caused by an overgrowth of fungus called "Malassezia furfur" which may also be found on normal skin
Beach fungus has nothing to do with the beach, but it is a fungal infection which may take some time to treat. The name beach fungus comes from it becoming more visible due to tanning of the surrounding skin after sun exposure.
No it can appear all year round as your skin is exposed to warm and humid conditions
Beach Fungus is not contagious, and you can not spread it or receive it from anyone else. It is over growth of fungus that is normally found on your skin "Malassezia furfur" which is due to exposure to warm and humid conditions
Some people seem prone to this fungus multiplying on their skin and the rash may come back after treatment. It is helpful to let your skin breath and avoid excess exposure to warm humid conditions.