Sumba weather by month: temperature, rain and the best time to go

Sumba has two seasons, but they are not the same everywhere on the island. The east, around Waingapu, is one of the driest corners of Indonesia, with brown savanna for months. The hills of West Sumba around Waikabubak are greener, cooler and rainier. This guide uses ten years of daily weather data (2015 to 2024) to show what each month is really like, and what that means for your trip.

The short answer

• Best overall: May to October, the dry season: sunny, dry roads, calmer travel.
• Greenest landscapes: January to April, when the hills and rice fields are bright green and waterfalls are full.
• Pasola: February and March in West and Southwest Sumba; see our Pasola guide.
• Hottest: October and November, just before the rains.

Climate tables

Average daily maximum and minimum temperatures and monthly rainfall. The data come from the Open-Meteo historical weather service (ERA5 reanalysis, a weather model), averaged for 2015 to 2024. Models tend to overestimate rain in dry places, so read the rain column as a guide to the pattern rather than an exact figure.

Waingapu and East Sumba

Month	Max °C	Min °C	Rain (mm, model)
Jan	31	25	263
Feb	30	25	251
Mar	30	25	251
Apr	30	24	139
May	30	24	36
Jun	30	23	21
Jul	30	22	15
Aug	31	22	10
Sep	32	23	17
Oct	32	24	43
Nov	32	25	123
Dec	31	25	232

Tambolaka and the Kodi coast (Southwest Sumba)

Month	Max °C	Min °C	Rain (mm, model)
Jan	29	25	260
Feb	29	24	260
Mar	29	24	245
Apr	30	24	175
May	30	24	67
Jun	30	23	42
Jul	30	22	38
Aug	30	22	27
Sep	31	22	36
Oct	32	24	78
Nov	31	25	117
Dec	30	25	211

Waikabubak and the West Sumba highlands

Month	Max °C	Min °C	Rain (mm, model)
Jan	28	22	271
Feb	28	22	280
Mar	28	22	289
Apr	28	21	214
May	28	20	83
Jun	28	20	57
Jul	27	18	42
Aug	28	19	45
Sep	29	19	85
Oct	30	21	147
Nov	30	22	191
Dec	28	22	261

The south coast (around Tarimbang)

Month	Max °C	Min °C	Rain (mm, model)
Jan	29	25	337
Feb	29	24	282
Mar	30	24	254
Apr	30	24	196
May	30	24	44
Jun	30	23	30
Jul	30	22	22
Aug	30	22	27
Sep	30	22	48
Oct	31	24	77
Nov	31	24	136
Dec	30	25	278

Month by month

January to March

The heart of the wet season. Rain usually comes as heavy showers rather than all-day drizzle, often in the afternoon or at night, and there are sunny spells. The island is at its greenest, and waterfalls such as Lapopu and Tanggedu are powerful, though some can be muddy and some paths slippery. Unpaved roads can be difficult. February and March bring the Pasola.

April

A transition month: rain eases, especially in the east, while the hills are still green. A good compromise between landscapes and dry roads.

May and June

The dry season settles in. Skies are clear, the savanna begins to turn gold and travel is easy. Many visitors consider this the sweet spot.

July to September

The driest and, in the west and highlands, the coolest months, with fresh nights in Waikabubak. It is peak season for travel, so book flights early. The south and west coasts receive big swells from the Indian Ocean, good for surfing, see surfing in Sumba, but not for swimming on exposed beaches.

October and November

The hottest time of year, especially in East Sumba where daytime highs reach about 32 °C. Some waterfalls are thin. The first rains usually arrive in November.

December

The rains return; the landscape turns green within weeks. Holiday flights fill up around Christmas and New Year.

Weather tips

• Check the live forecast for the four towns on our Sumba weather page.
• Even in the dry season, bring a light rain jacket for the highlands.
• The sun is strong all year at 10° south: use sunscreen, a hat and water.
• In the wet season, plan the longest drives for the morning.