April to June: April is the very start of Java’s dry season, although frequent heavy showers are to be expected in this month. The benefit of travelling to Java in April is that after the rains the paddy fields are in their full verdant bloom, so this is a good time for photographers if you are lucky with clear skies. Java’s weather in May becomes more reliable, with less frequent showers and longer periods of sunshine, making this a great month for hiking at Mount Bromo and Ijen. This trend continues through this period leading up to the busier months of July and August, making June one of the best months to visit Java.
July and August: The driest months in Java are July and August, and humidity is at its lowest, making this the optimum time to visit the island. These ideal conditions attract higher number of visitors, so popular places such as Borobudur, Prambanan and Mount Bromo can get very busy during these months. Booking early is advisable if you wish to travel at this time of the year.
September and October: Both September and October are an optimum time to visit Java. Temperatures start rising slightly in September, but rainfall remains very low. Java’s visitor numbers decrease as you get further into September and October, and with fewer visitors the popular sights are less crowded than in the peak summer months. As the heat builds Java’s rainfall starts increasing in October, especially in the western areas such as Jakarta and Bandung, but this normally takes the form of afternoon downpours.
November to March: Rainfall increases towards the end of the year, peaking in January which is considered to be Java’s wettest month of the year. The eastern part of Java remains fairly dry in November, so this month is fine for visiting the cultural sights around Yogyakarta, Borobudur, Mount Bromo and Ijen. Between December and February expect cloudy skies and frequent thunderstorms throughout Java. From March the conditions start improving with rain falling in sharp showers dispersed with periods of clear skies.
Idul Fitri: In the weeks that follow the Muslim fasting month of Ramadhan the Indonesian people celebrate a national holiday of Idul Fitri. In the build-up to this important festival millions of Indonesians are on the move back to their family homes to feast and celebrate the end of fasting. All airports, trains and roads are heavily congested, so it is best to avoid visiting Java in the week before and after Idul Fitri.