Sumba Island Weather: A Month-by-Month Guide for Travelers

Understanding Sumba’s weather patterns is essential for planning the perfect trip. Located at approximately 10° south of the equator, Sumba experiences a tropical climate with two distinct seasons. This month-by-month guide helps you know exactly what to expect — from temperatures and rainfall to ocean conditions and activity recommendations.

January

Temperature: 26-32°C. Rainfall: 200-300mm (high). Humidity: 80-85%. This is peak wet season. Expect daily afternoon thunderstorms, often heavy. Mornings are frequently clear and suitable for horse riding. Roads to remote areas may be muddy. Waterfalls at maximum flow. Lush green landscapes. Lowest tourist numbers and prices.

February

Temperature: 26-32°C. Rainfall: 200-280mm (high). The wet season continues, but this is Pasola season — Sumba’s famous mounted jousting ceremony begins in late February in Lamboya and Wanokaka. Despite the rain, this is a thrilling time to visit for cultural travelers. See our Pasola guide.

March

Temperature: 26-32°C. Rainfall: 180-250mm (moderate-high). Pasola ceremonies continue in Gaura and Kodi. Rains begin easing slightly toward month’s end. The landscape is at its most vibrant green. A good month for combining cultural experiences with careful weather-window horse riding.

April

Temperature: 27-32°C. Rainfall: 80-150mm (moderate). The transition month — rains decrease significantly but have not stopped entirely. An excellent time to visit: green scenery, strong waterfall flows, improving beach conditions, and lower prices than peak season. Beach riding becomes more reliable.

May

Temperature: 27-31°C. Rainfall: 30-70mm (low). The dry season begins. Clear skies, comfortable temperatures, and calm seas make this an ideal month for all activities. Tourist numbers are moderate. Waterfalls still flowing well. This may be the best overall month to visit Sumba — great conditions without peak-season crowds.

June

Temperature: 26-30°C. Rainfall: 10-30mm (very low). Peak dry season begins. Excellent conditions for beach riding, horse swimming, and sunset rides. The southeast trade winds bring a pleasant cooling breeze. Surf season kicks into gear. Book in advance as tourist numbers increase.

July

Temperature: 25-30°C. Rainfall: 5-15mm (minimal). The coolest and driest month — virtually no rain and comfortable temperatures. This is peak tourist season. Book accommodation and activities well in advance. Perfect conditions for every outdoor activity. Landscapes are golden-brown, giving Sumba its distinctive savanna appearance.

August

Temperature: 25-30°C. Rainfall: 5-15mm (minimal). Similar to July — peak season continues with the driest conditions. The strongest trade winds make this the best surf month. All horse riding experiences operate at full capacity. Highest demand for accommodation.

September

Temperature: 26-31°C. Rainfall: 15-40mm (low). Late dry season with excellent conditions. Tourist numbers begin to decrease, creating a sweet spot of good weather and more availability. Temperatures warm slightly. Our recommended month for travelers wanting dry-season quality without peak-season competition.

October

Temperature: 27-32°C. Rainfall: 50-100mm (moderate). Transition month — occasional afternoon showers return but most days remain predominantly dry. The landscape begins greening. Good conditions for all activities with the lowest prices of the favorable-weather period. An underrated time to visit.

November

Temperature: 27-33°C. Rainfall: 100-200mm (moderate-high). The wet season returns with increasing afternoon storms. Mornings remain suitable for activities. Waterfalls begin strengthening. Tourist numbers drop significantly. Good value month for flexible travelers.

December

Temperature: 27-33°C. Rainfall: 150-250mm (high). Full wet season. Daily storms likely, though mornings are often clear. Christmas and New Year bring a brief tourist spike despite the weather. Green landscapes, dramatic cloud formations, and spectacular storm sunsets appeal to photographers.

Planning Around the Weather

For the most reliable conditions, visit between May and September. For the best value, consider April, October, or November. For cultural events, February-March is essential for Pasola. For detailed seasonal planning, see our best time to visit Sumba guide, or contact us to discuss optimal timing for your trip.