According to Schmits and Ferguson's climate classification, Karimunjawa Marine National Park is categorized in type C climate areas with average rainfalls of 3.000 mm per year.
The average temperature in this area is between 26°C to 30°C, with minimum temperature is 22°C and maximum is 34°C.
Generaly rain drops all the year (but this doesn't mean that rain drops everyday J).
From April to October is the dry season, so less rain in this period. Mostly in month of June, average raining is just 1 day.
The wet season is last during November to March. In this period, you will get more rainy days, sometime accompanied by strong winds that will caused big waves which usually comes often in July and August.
So consider very well the best season to visit this area, otherwise you will get disappointed for can't doing everything what you have planned to do here.
Most of the islands are surrounded by white sand beaches and coral reefs with colorful plateaus and plains in deep and shallow clear water.
Here also can be found many kinds of fauna such as deer, long tail monkeys, sea turtles, white-chested sea eagle, and many kinds of aquatic fauna such as more than 240 variety of decorative fish, shark, starfish, red snapper, jelly fish, dolphin, and some rare ones such as crocodile fish and leafy scorpion fish.