BMKG Weekly Outlook: What 18–24 September 2026 Means for Komodo Trips

Labuan Bajo — Indonesia’s meteorological agency BMKG is forecasting mostly dry, sunny conditions with pockets of moderate to heavy rain and strong winds in parts of the country between 18 and 24 September 2026, but it does not issue any specific rain warning or closure notice for West Manggarai, Labuan Bajo or Komodo waters in its national weekly outlook.

In its 18–24 September 2026 weekly forecast, BMKG states that much of Indonesia will continue to experience a dry atmosphere due to a very strong El Niño, with overall rainfall in many regions remaining in the low to medium range of roughly 0–150 mm per ten‑day period. The agency warns, however, that rain from moderate to very heavy intensity can still develop locally where atmospheric waves, wind convergence and cyclonic circulation are active.

Rain and wind potential by region

BMKG’s outlook notes that rain remains possible from 18–24 September 2026 in northern and central parts of Sumatra, northern to central Kalimantan, central to southern Sulawesi, the Papua Highlands and Papua. These areas are highlighted as zones where showers and thunderstorms may interrupt otherwise dry-season conditions.

The agency further identifies an increase in moderate rain potential in provinces including Aceh, Riau, the Riau Islands, Jambi, South Sumatra, Bengkulu, Lampung, Central Java, East Java, West Kalimantan, Central Kalimantan, East Kalimantan, North Kalimantan, Central Sulawesi, West Sulawesi, Central Papua, the Papua Highlands and Papua. In addition, BMKG lists Aceh and West Sumatra in a “alert” category for heavy to very heavy rain early in the period, suggesting a higher likelihood of intense downpours and associated hazards.

The same forecast highlights strong-wind potential in several provinces, including East Nusa Tenggara, which covers West Manggarai and Labuan Bajo. BMKG classifies East Nusa Tenggara among the regions where gusty winds are more likely during the week, alongside parts of Aceh, Sulawesi and Maluku. However, the document does not break down conditions by individual districts or marine zones such as Komodo National Park.

El Niño and dry-season risks

BMKG’s broader climate analysis for early September 2026 reports that the ENSO index places El Niño firmly in the “very strong” category, with sea-surface temperature anomalies in the Niño 3.4 region around +2.6 to +2.76°C. According to BMKG, this pattern is maintaining a predominantly dry atmosphere over much of Indonesia, reducing cloud cover and increasing daytime temperatures.

The agency warns that the prolonged dry season is contributing to drought and an elevated risk of land and forest fires in several regions. BMKG notes that many southern parts of Indonesia, including Nusa Tenggara, have experienced “extreme” stretches of more than 60 consecutive days without rain, reinforcing the need for water conservation and careful handling of fire sources.

Implications for Komodo trips

For visitors planning boat trips and dives from Labuan Bajo, the weekly outlook indicates that the main national concern remains heat, dryness and fire risk, with localized rain and strong winds possible rather than guaranteed across all areas of East Nusa Tenggara. BMKG’s published forecast does not specify wind speeds, wave heights or visibility for Komodo waters, nor does it mention any sailing or trekking restrictions for the park.

Conditions can vary significantly between the harbour, open channels, island anchorages and hilltop trekking routes. Travellers are therefore advised to check the latest local marine and short‑term weather bulletins from BMKG and harbour authorities before departure, and to follow decisions made by boat captains and park officials on the day of travel.

Even moderate rain can affect comfort and safety by reducing visibility, making decks and trails slippery, and complicating wet landings at beaches and jetties. Strong winds may influence route choices and sea conditions, particularly for smaller vessels.

Given the continuing influence of very strong El Niño, BMKG also recommends practical preparations for heat: adequate hydration, sun protection, and attention to fire safety in dry vegetation areas near campsites, resorts and villages.

Sources

• BMKG – Prakiraan Cuaca Indonesia Sepekan Periode 18–24 September 2026: El Nino Sangat Kuat Masih Berdampak, Tetap Waspada Hujan Akibat Fenomena Atmosfer di Seba
• Tribunnews – Prakiraan Cuaca Indonesia 18–24 September 2026: El Nino Sangat Kuat, Waspada Cuaca Ekstrem
• Bloomberg Technoz – Cuaca Pekan Depan: Cerah-Hujan Sedang, Dipengaruhi El-Nino