Indonesia Weather by Month
Indonesia is the largest archipelago in the world, consisting of over 17,000 islands located between the Indian and Pacific Oceans. It is situated in Southeast Asia and Oceania, straddling the equator, which gives it a predominantly tropical climate. The country shares land borders with Malaysia, Papua New Guinea, and East Timor. Indonesia’s major islands include Java, Sumatra, Borneo (shared with Malaysia and Brunei), Sulawesi, and New Guinea (shared with Papua New Guinea).
The topography of Indonesia is incredibly diverse, ranging from low-lying coastal plains and lush rainforests to towering volcanic peaks. The country’s islands are home to numerous active and dormant volcanoes, with some of the most famous being Mount Merapi on Java and Mount Rinjani on Lombok. Indonesia’s tropical rainforests are among the most biodiverse in the world, home to unique wildlife such as orangutans, Komodo dragons, and Sumatran tigers. Indonesia’s climate is largely influenced by the monsoons, resulting in distinct wet and dry seasons. The country’s weather can vary significantly by region, as the northernmost and southernmost islands experience different monsoon patterns. Understanding Indonesia’s weather by month is crucial for travelers, residents, and anyone involved in agriculture or maritime activities.
Indonesia’s Weather by Month
January: Peak of the Rainy Season
Sumatra and Java (Medan, Jakarta)
- Average Temperature: 27°C (81°F) during the day, 23°C (73°F) at night
- Rainfall: Heavy, around 300-400 mm
- Humidity: Very high, around 85-90%
- Winds: Light to moderate, with occasional thunderstorms
Bali and Lombok
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Heavy, around 300 mm
- Humidity: Very high, around 85-90%
- Winds: Light breezes, with frequent rain showers
Sulawesi and Papua
- Average Temperature: 27°C (81°F) during the day, 23°C (73°F) at night
- Rainfall: Moderate to heavy, around 250-300 mm
- Humidity: High, around 80-85%
- Winds: Light winds, with afternoon thunderstorms
Summary: January is one of the wettest months across Indonesia, particularly on the islands of Sumatra, Java, Bali, and Lombok. Heavy rainfall and high humidity levels dominate, making it challenging for outdoor activities. Thunderstorms are frequent, but temperatures remain warm. Coastal areas may experience flooding and transportation delays, but the rain transforms the landscape into a lush green paradise.
February: Wet and Humid
Sumatra and Java
- Average Temperature: 27°C (81°F) during the day, 23°C (73°F) at night
- Rainfall: Heavy, around 300-400 mm
- Humidity: Very high, around 85-90%
- Winds: Light to moderate, with thunderstorms common in the afternoons
Bali and Lombok
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Heavy, around 300 mm
- Humidity: Very high, around 85-90%
- Winds: Light breezes, with regular rain showers
Sulawesi and Papua
- Average Temperature: 27°C (81°F) during the day, 23°C (73°F) at night
- Rainfall: Moderate to heavy, around 250-300 mm
- Humidity: High, around 80-85%
- Winds: Light winds, with afternoon thunderstorms
Summary: February continues to be a very wet month across much of Indonesia, with high rainfall and humidity levels. Rain showers are frequent, and flooding can still be a concern, especially in low-lying areas. However, the rain is generally interspersed with periods of sunshine, making it possible to enjoy some outdoor activities between showers.
March: End of the Rainy Season
Sumatra and Java
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Moderate, around 250-300 mm
- Humidity: High, around 80-85%
- Winds: Light to moderate, with scattered thunderstorms
Bali and Lombok
- Average Temperature: 29°C (84°F) during the day, 25°C (77°F) at night
- Rainfall: Moderate, around 200-250 mm
- Humidity: High, around 80-85%
- Winds: Light breezes, with occasional showers
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Moderate, around 200-250 mm
- Humidity: High, around 80-85%
- Winds: Light to moderate, with thunderstorms in the afternoon
Summary: March marks the tail end of the rainy season in Indonesia, with rainfall beginning to taper off. While the weather remains humid and wet, there are more frequent dry spells, and thunderstorms are less intense. This month is still not ideal for extensive outdoor activities, but visitors can expect fewer disruptions from rain than in the previous months.
April: Transition to the Dry Season
Sumatra and Java
- Average Temperature: 29°C (84°F) during the day, 25°C (77°F) at night
- Rainfall: Moderate, around 150-200 mm
- Humidity: High, around 75-80%
- Winds: Light, with occasional showers
Bali and Lombok
- Average Temperature: 30°C (86°F) during the day, 25°C (77°F) at night
- Rainfall: Light to moderate, around 150 mm
- Humidity: High, around 75-80%
- Winds: Light breezes, with fewer rain showers
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Moderate, around 150-200 mm
- Humidity: High, around 75-80%
- Winds: Light, with occasional thunderstorms
Summary: April brings a noticeable reduction in rainfall, especially in central and eastern Indonesia. While showers and thunderstorms still occur, they are less frequent, and the humidity begins to drop slightly. The islands of Bali and Lombok start experiencing more dry days, making it a better time for tourists to visit beaches and engage in outdoor adventures.
May: Beginning of the Dry Season
Sumatra and Java
- Average Temperature: 30°C (86°F) during the day, 26°C (79°F) at night
- Rainfall: Light, around 100-150 mm
- Humidity: Moderate to high, around 70-75%
- Winds: Light, with occasional breezes
Bali and Lombok
- Average Temperature: 31°C (88°F) during the day, 26°C (79°F) at night
- Rainfall: Light, around 100 mm
- Humidity: Moderate to high, around 70%
- Winds: Light to moderate breezes, with sunny conditions
Sulawesi and Papua
- Average Temperature: 29°C (84°F) during the day, 25°C (77°F) at night
- Rainfall: Light, around 100-150 mm
- Humidity: High, around 75-80%
- Winds: Light, with afternoon showers
Summary: May marks the start of the dry season in many parts of Indonesia, with rainfall significantly reduced across the country. This is an excellent time for travel, especially for beachgoers and outdoor adventurers. Temperatures remain warm, and humidity levels drop slightly, making the weather more comfortable, particularly in coastal regions like Bali, Lombok, and Java.
June: Dry Season in Full Swing
Sumatra and Java
- Average Temperature: 30°C (86°F) during the day, 25°C (77°F) at night
- Rainfall: Minimal, around 50-100 mm
- Humidity: Moderate, around 65-70%
- Winds: Light to moderate, with dry and sunny days
Bali and Lombok
- Average Temperature: 30°C (86°F) during the day, 25°C (77°F) at night
- Rainfall: Minimal, around 50 mm
- Humidity: Moderate, around 65%
- Winds: Light breezes, with clear skies
Sulawesi and Papua
- Average Temperature: 29°C (84°F) during the day, 24°C (75°F) at night
- Rainfall: Light, around 100 mm
- Humidity: Moderate to high, around 70%
- Winds: Light to moderate, with occasional showers
Summary: June is well into the dry season in Indonesia, particularly in the western and central parts of the country. Rainfall is minimal, and the weather is warm and sunny, ideal for beach vacations and outdoor activities. Islands like Bali and Lombok enjoy clear skies, while eastern regions like Sulawesi and Papua still receive light showers but remain largely dry.
July: Peak Dry Season
Sumatra and Java
- Average Temperature: 29°C (84°F) during the day, 24°C (75°F) at night
- Rainfall: Very minimal, around 20-50 mm
- Humidity: Low to moderate, around 60-65%
- Winds: Light to moderate, with sunny and dry conditions
Bali and Lombok
- Average Temperature: 30°C (86°F) during the day, 24°C (75°F) at night
- Rainfall: Very minimal, around 20-50 mm
- Humidity: Moderate, around 65%
- Winds: Light breezes, with ideal beach conditions
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Light, around 80-100 mm
- Humidity: Moderate to high, around 70-75%
- Winds: Light, with occasional showers
Summary: July is one of the driest months across Indonesia, making it a prime time for tourism, especially in the popular destinations of Bali, Java, and Sumatra. The weather is warm, sunny, and perfect for outdoor activities such as hiking, surfing, and snorkeling. Eastern regions like Sulawesi and Papua continue to experience light showers, but overall, the country enjoys excellent travel conditions.
August: Warm and Dry
Sumatra and Java
- Average Temperature: 29°C (84°F) during the day, 24°C (75°F) at night
- Rainfall: Very minimal, around 20-50 mm
- Humidity: Low to moderate, around 60-65%
- Winds: Light, with clear skies and dry weather
Bali and Lombok
- Average Temperature: 30°C (86°F) during the day, 24°C (75°F) at night
- Rainfall: Very minimal, around 20-40 mm
- Humidity: Moderate, around 65%
- Winds: Light breezes, with perfect beach conditions
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Light, around 80-100 mm
- Humidity: High, around 70-75%
- Winds: Light, with occasional showers
Summary: August continues the peak of the dry season in Indonesia, with minimal rainfall and sunny, warm weather. Bali and Lombok, in particular, are ideal for tourists, with perfect beach conditions and clear skies. Eastern regions still receive occasional showers, but the weather remains largely dry and warm. Overall, August is one of the best months to visit Indonesia.
September: Dry Season Continues
Sumatra and Java
- Average Temperature: 29°C (84°F) during the day, 24°C (75°F) at night
- Rainfall: Light, around 50-100 mm
- Humidity: Moderate, around 65-70%
- Winds: Light, with occasional breezes
Bali and Lombok
- Average Temperature: 30°C (86°F) during the day, 24°C (75°F) at night
- Rainfall: Light, around 50-100 mm
- Humidity: Moderate, around 65%
- Winds: Light breezes, with clear skies
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Light to moderate, around 100-150 mm
- Humidity: High, around 70-75%
- Winds: Light to moderate, with occasional showers
Summary: September is another excellent month for travel in Indonesia, as the dry season continues. Rainfall remains low across most regions, particularly in the western and central islands. Temperatures are warm, and humidity levels are moderate, making it comfortable for outdoor activities. Eastern regions may see more showers, but overall, the weather remains favorable for travel and exploration.
October: Start of the Rainy Season
Sumatra and Java
- Average Temperature: 30°C (86°F) during the day, 25°C (77°F) at night
- Rainfall: Moderate, around 100-150 mm
- Humidity: High, around 75-80%
- Winds: Light to moderate, with afternoon thunderstorms
Bali and Lombok
- Average Temperature: 31°C (88°F) during the day, 25°C (77°F) at night
- Rainfall: Moderate, around 100-150 mm
- Humidity: High, around 75-80%
- Winds: Light breezes, with increasing rain showers
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Moderate to heavy, around 150-200 mm
- Humidity: High, around 75-80%
- Winds: Light to moderate, with afternoon thunderstorms
Summary: October marks the beginning of the rainy season in Indonesia, with increased rainfall and higher humidity levels. While dry days are still common, the frequency of afternoon showers and thunderstorms increases. Bali, Lombok, and Java begin to experience more rain, though travel is still possible with proper planning. Eastern regions like Sulawesi and Papua see heavier rain and more frequent thunderstorms.
November: Rain Intensifies
Sumatra and Java
- Average Temperature: 29°C (84°F) during the day, 25°C (77°F) at night
- Rainfall: Heavy, around 200-250 mm
- Humidity: Very high, around 80-85%
- Winds: Light to moderate, with frequent thunderstorms
Bali and Lombok
- Average Temperature: 30°C (86°F) during the day, 25°C (77°F) at night
- Rainfall: Heavy, around 200-250 mm
- Humidity: Very high, around 80-85%
- Winds: Light, with regular rain showers
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Very heavy, around 250-300 mm
- Humidity: Very high, around 85%
- Winds: Light to moderate, with afternoon thunderstorms
Summary: November sees a significant increase in rainfall across much of Indonesia. The wet season is now in full swing, with heavy showers and thunderstorms becoming a daily occurrence, particularly in the afternoons. Travel plans should take into account the possibility of rain, especially in eastern regions where rainfall is heaviest. Coastal flooding may occur in low-lying areas.
December: Peak of the Rainy Season
Sumatra and Java
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Very heavy, around 300-350 mm
- Humidity: Extremely high, around 85-90%
- Winds: Light to moderate, with frequent thunderstorms and downpours
Bali and Lombok
- Average Temperature: 29°C (84°F) during the day, 24°C (75°F) at night
- Rainfall: Very heavy, around 300-350 mm
- Humidity: Very high, around 85-90%
- Winds: Light breezes, with regular rainstorms
Sulawesi and Papua
- Average Temperature: 28°C (82°F) during the day, 24°C (75°F) at night
- Rainfall: Very heavy, around 300-350 mm
- Humidity: Extremely high, around 85-90%
- Winds: Light to moderate, with frequent thunderstorms
Summary: December is one of the wettest months in Indonesia, with heavy rainfall and very high humidity levels across the country. Thunderstorms are frequent, and flooding can occur in vulnerable areas, particularly along the coasts and in river basins. Outdoor activities are often disrupted by rain, but the lush, green landscapes make for beautiful scenery. This month requires careful planning for travel due to the frequent downpours.
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