Indonesia Braces for Prolonged, Intense Drought as El Niño Persists Until Early 2027, Potentially Amplified by Positive IOD

Jakarta, Indonesia – Indonesia is facing a severe and protracted dry season, with the nation’s meteorological agency, the Badan Meteorologi, Klimatologi, dan Geofisika (BMKG), issuing stark warnings about the persistence of El Niño until at least the first quarter of 2027. This formidable climate phenomenon is projected to reach an intensity exceeding the "strong" category, threatening to usher in one of the most challenging arid periods in recent memory. Compounding this risk is the potential activation of a Positive Indian Ocean Dipole (IOD) between September and December 2026, a confluence of climatic events that could significantly exacerbate drought conditions across the archipelago.

The implications are far-reaching, from escalating risks of forest and land fires (Karhutla) to widespread agricultural disruptions, water scarcity, and public health concerns. With a majority of Indonesia’s regions already experiencing varying degrees of rainfall deficit, the government and communities are urged to brace for an extended period of dryness that demands heightened vigilance and proactive mitigation strategies.

A Looming Climatic Crisis: Main Facts

The BMKG’s latest assessments paint a sobering picture for Indonesia’s climatic future over the next year and a half. The primary drivers of this impending crisis are:

• Persistent and Strong El Niño: El Niño is forecast to endure until early Q1 2027, with its intensity already surpassing the "strong" category threshold. The monthly Nino 3.4 index, a key indicator, registered 1.56 at the end of June, exceeding the >1.5 benchmark for a strong event.
• Potential Positive Indian Ocean Dipole (IOD): A significant likelihood exists for a Positive IOD event to emerge between September and December 2026. This phenomenon, characterized by anomalous cooling of sea surface temperatures in the eastern Indian Ocean, typically reduces rainfall over western Indonesia, thereby intensifying the drying effects of El Niño.
• Widespread Drought: A staggering 437 Seasonal Zones (ZOMs), representing approximately 48.77% of Indonesia’s land area, are anticipated to experience a drier and longer dry season than normal.
• Current Rainfall Deficit: As of mid-July 2026, 509 ZOMs (approximately 54.5% of Indonesia’s total land area) have already entered the dry season. The longest recorded "days without rain" (HTH) reached 80 days in Katerban, Kaligesing, Purworejo Regency, Central Java.
• Peak Dry Season: The peak of the dry season is projected for August 2026, affecting 48.84% of the land area, followed by September 2026, impacting 25.41%.
• Escalating Hotspots: The arid conditions are already contributing to a significant increase in hotspots, with 5,019 detected by July 29, 2026. These are predominantly concentrated in West Kalimantan, South Papua, and Riau, areas historically vulnerable to Karhutla.
• Delayed Rainfall Return: Significant high rainfall is not expected to return gradually until October to November 2026.

Chronology of an Evolving Climate Threat

Understanding the timeline of these climate phenomena is crucial for effective preparedness and response.

Early 2026:
The early months of 2026 saw the initial signs of strengthening El Niño conditions. While its effects were not yet fully pronounced across Indonesia, BMKG began its intensified monitoring, noting the gradual warming of sea surface temperatures in the central and eastern equatorial Pacific Ocean, characteristic of El Niño’s formation. Weather patterns across Indonesia started showing slight anomalies, with some regions experiencing a delayed onset of the wet season or an earlier-than-usual transition to drier conditions.

Mid-2026 (Leading up to July):
By the end of June, the scientific community’s concerns escalated as the El Niño reached a critical threshold. The Nino 3.4 index, a crucial metric for El Niño’s strength, surged past 1.56, officially classifying the event as "strong." This marked a significant turning point, indicating a much higher likelihood of severe impacts compared to moderate El Niño events.

Throughout July, the dry season firmly established itself across large swathes of the archipelago. BMKG data confirmed that by mid-July, over half of Indonesia’s land area, encompassing 509 ZOMs, had officially transitioned into the dry period. Reports of "days without rain" (HTH) became more frequent and prolonged, with specific locations like Purworejo in Central Java registering an alarming 80 consecutive days without precipitation. Concurrently, the first noticeable increase in hotspots began to emerge, particularly in regions known for agricultural burning and forest concessions.

Late 2026 (Projected Peak and IOD Influence):
The coming months are predicted to be the most critical. August is forecast to be the peak of the dry season, affecting nearly half of Indonesia’s landmass. This will be followed closely by September, which will still see a quarter of the country grappling with peak aridity.

Crucially, the period between September and December 2026 is when the potential for a Positive Indian Ocean Dipole (IOD) becomes a significant concern. BMKG’s monitoring of sea surface temperatures in the Indian Ocean, which currently sits at -0.386, indicates a substantial probability of this phenomenon activating. If it materializes, the Positive IOD will act as a potent amplifier, reducing rainfall even further, particularly in the western parts of Indonesia, which are already susceptible to El Niño’s drying influence. This dual climate event is expected to create a "double whammy," intensifying drought conditions beyond what either phenomenon might cause in isolation.

Early 2027:
While the most severe impacts are concentrated in late 2026, El Niño’s influence is projected to persist until the early months of 2027. This means that even as the calendar turns, residual dryness and the lingering effects of the prolonged drought will continue to be felt across various sectors, from agriculture to water resources. The gradual return of significant rainfall is only anticipated to begin in October to November 2026, implying a protracted period before full recovery from the drought’s effects can commence.

Supporting Data: A Nation Under Pressure

The BMKG’s detailed meteorological observations and projections underscore the scale of the challenge:

• El Niño Intensity: The Nino 3.4 index, which measures sea surface temperature anomalies in a specific region of the equatorial Pacific, registered 1.56 at the end of June 2026. This figure surpasses the critical threshold of >1.5, which defines a "strong" El Niño event. For context, strong El Niños historically correlate with significant rainfall deficits and heightened drought risks across Indonesia.
• Indian Ocean Dipole (IOD) Indicator: The current sea surface temperature anomaly in the Indian Ocean stands at -0.386. While this value itself doesn’t confirm a Positive IOD, it indicates a significant predisposition for the phenomenon to develop in the coming months, particularly from September to December 2026. A Positive IOD typically involves warmer-than-average sea surface temperatures in the western Indian Ocean and cooler-than-average temperatures in the eastern Indian Ocean, disrupting atmospheric circulation and reducing rainfall over Indonesia.
• Seasonal Zones (ZOMs) Status:
  • Dry Season Entry: As of mid-July 2026, 509 ZOMs, constituting approximately 54.5% of Indonesia’s total land area, have already entered the dry season. A ZOM is a localized area with a distinct seasonal rainfall pattern, used by BMKG for more precise climate forecasting and agricultural planning.
  • Wet Season Persistence: A smaller fraction, 77 ZOMs (11.8%), continues to experience the wet season. These are typically areas influenced by local topography or specific wind patterns that sustain rainfall.
  • Single-Season Regions: Another 113 ZOMs (33.7%) are categorized as "single-season" areas, meaning they do not exhibit clear wet and dry seasons but rather receive relatively consistent rainfall throughout the year, or have a less distinct seasonal shift.
• Prolonged Dryness: A significant 437 ZOMs (48.77% of the land area) are projected to experience a drier-than-normal and longer-than-normal dry season. This extended duration amplifies the cumulative impact of water stress on agriculture, ecosystems, and human populations.
• Days Without Rain (HTH): The "Hari Tanpa Hujan" (HTH) metric measures consecutive days without significant rainfall (typically less than 5mm). The record of 80 days in Purworejo, Central Java, highlights extreme localized drought conditions. Other regions are also experiencing HTH in categories ranging from "very short" (1-5 days) to "long" (31-60 days) and "very long" (>60 days), indicating a widespread and varied impact across the archipelago.
• Hotspot Proliferation: By July 29, 2026, BMKG had detected 5,019 hotspots across Indonesia. These thermal anomalies, often indicative of land clearing fires or uncontrolled burning, are a direct consequence of the dry conditions. The dominant regions are West Kalimantan, South Papua, and Riau, areas historically prone to large-scale forest and land fires that produce transboundary haze.

Official Responses and Expert Insights

The BMKG, as the nation’s primary authority on meteorology, climatology, and geophysics, plays a pivotal role in monitoring these complex phenomena and communicating their implications.

Ardhasena Sopaheluwakan, Deputy for Climatology at BMKG, emphasized the critical interplay between El Niño and Indonesia’s seasonal cycle. "Based on BMKG observations at the end of June, the monthly Nino 3.4 index has already reached 1.56. This indicates that El Niño’s intensity has exceeded the strong category threshold (>1.5)," Ardhasena stated. He further highlighted the potential for a Positive IOD, noting, "Furthermore, current sea surface temperatures in the Indian Ocean are still at -0.386, indicating a significant likelihood of a Positive Indian Ocean Dipole (IOD) emerging in the coming period."

Ardhasena underscored a crucial nuance regarding El Niño’s impact: "However, it needs to be underlined that its impact on Indonesia occurs when El Niño directly coincides with the dry season. Although El Niño will continue until early 2027, its primary impact is focused on the dry season period in Indonesian territory." This statement clarifies that while El Niño may persist, its most acute effects—reduced rainfall and heightened drought—are predominantly felt during Indonesia’s dry months, which are currently underway and peaking.

The BMKG’s role extends beyond mere forecasting; it involves issuing timely warnings, providing data to various government agencies, and advising on mitigation strategies. Their assessments are crucial for informing policy decisions related to agriculture, water management, disaster preparedness, and public health. The agency consistently advocates for a multi-sectoral approach, emphasizing that addressing the challenges posed by El Niño and IOD requires coordinated efforts from central and regional governments, communities, and relevant ministries.

Far-Reaching Implications for Society and Economy

The combined threat of a strong, persistent El Niño and a potential Positive IOD carries severe implications across multiple facets of Indonesian life.

1. Agriculture and Food Security:
The agricultural sector, a cornerstone of Indonesia’s economy and livelihood for millions, is particularly vulnerable. A prolonged and drier-than-normal dry season directly threatens crop yields, especially for rain-fed staples like rice, corn, and soybeans. Water scarcity will reduce irrigation capabilities, leading to crop failures, delayed planting seasons, and potentially significant losses for farmers. This, in turn, could trigger increases in food prices, exacerbating food insecurity for vulnerable populations and potentially necessitating large-scale food imports, impacting national reserves and the economy. Livestock also faces challenges due to diminished pasture and water sources.

2. Water Resources Management:
Reduced rainfall will lead to a drastic decrease in water availability. Rivers will shrink, reservoirs and dams will see critically low levels, impacting hydro-power generation and municipal water supplies. Communities, particularly those in rural areas, will struggle to access clean drinking water, increasing the risk of water-borne diseases. Industries reliant on water, such as manufacturing and mining, could also face operational challenges.

3. Forest and Land Fires (Karhutla) and Haze:
The dry conditions create an ideal environment for forest and land fires to ignite and spread rapidly. The surge in hotspots, especially in West Kalimantan, South Papua, and Riau, is a clear precursor to potential large-scale Karhutla. These fires not only cause immense ecological damage, destroying biodiversity and critical habitats, but also generate thick, transboundary haze. This haze poses severe public health risks, leading to acute respiratory infections (ARI), eye irritations, and reduced visibility, disrupting air travel and economic activities. The economic cost of Karhutla, including firefighting efforts, health impacts, and lost productivity, can run into billions of dollars.

4. Public Health Concerns:
Beyond haze-related illnesses, the prolonged drought can lead to other health crises. Heat stress and heatstroke become more prevalent as temperatures rise. Water scarcity can force communities to rely on unsafe water sources, increasing the incidence of diarrheal diseases, cholera, and other water-borne illnesses. Furthermore, changes in ecosystem dynamics due to drought can alter vector-borne disease patterns.

5. Economic Downturn:
The cumulative impact of agricultural losses, disrupted trade due to haze, reduced tourism (especially in affected areas), and increased healthcare costs could significantly dampen Indonesia’s economic growth. Sectors like fisheries might also suffer due to altered aquatic ecosystems and water temperatures. Government resources will be diverted towards disaster response and mitigation, straining national budgets.

6. Social and Environmental Degradation:
Drought can exacerbate existing social inequalities, with marginalized communities often bearing the brunt of water scarcity and food insecurity. Resource conflicts over dwindling water and land resources could emerge. Environmentally, prolonged drought stresses ecosystems, leading to habitat loss, increased pest outbreaks, and long-term degradation of land quality.

Proactive Measures and Long-Term Resilience

In light of BMKG’s dire warnings, proactive measures are not just recommended but imperative. A comprehensive, multi-layered approach involving various stakeholders is essential to mitigate the adverse effects of this prolonged dry spell.

1. Strengthening Early Warning Systems:
BMKG’s continuous monitoring and accurate forecasting are paramount. Enhancing data collection, predictive modeling, and dissemination of early warnings to central and regional governments, as well as directly to communities, is crucial. This includes clear, actionable advice tailored to specific regions and sectors.

2. Strategic Water Management:
With water scarcity being a central challenge, efficient water resource management is critical. This involves:

• Reservoir Optimization: Careful management of water levels in dams and reservoirs for irrigation, drinking water, and power generation.
• Water Conservation Campaigns: Promoting water-saving practices in households, agriculture, and industry.
• Alternative Water Sources: Exploring and investing in groundwater extraction, rainwater harvesting, and desalination technologies in coastal areas where feasible.
• Cloud Seeding: Implementing weather modification techniques (cloud seeding) to induce rainfall in critical areas, although its effectiveness can be limited during severe droughts.

3. Enhanced Fire Prevention and Suppression:
Given the heightened risk of Karhutla, robust fire management strategies are vital:

• Increased Patrols: Intensifying ground and aerial patrols in high-risk areas.
• Community Engagement: Educating local communities on the dangers of open burning and promoting alternative land clearing methods.
• Law Enforcement: Strictly enforcing anti-burning regulations and prosecuting perpetrators.
• Resource Allocation: Ensuring adequate firefighting equipment, personnel, and logistical support for rapid response.
• Peatland Restoration: Continuing efforts to restore degraded peatlands, which are highly susceptible to fires.

4. Agricultural Adaptation and Food Security:
To safeguard food security:

• Drought-Resistant Crops: Promoting the cultivation of drought-resistant crop varieties and adjusting planting schedules.
• Efficient Irrigation: Implementing drip irrigation and other water-efficient farming techniques.
• Food Reserves: Strengthening national and regional food reserves to buffer against potential shortages and price volatility.
• Farmer Support: Providing financial and technical assistance to farmers to cope with crop losses.

5. Public Health Preparedness:
Health ministries and local health departments must prepare for increased cases of respiratory illnesses, water-borne diseases, and heat-related conditions. This includes stocking medical supplies, activating public health campaigns, and ensuring access to clean water and sanitation facilities.

A Call for Unified Action

The BMKG’s forecasts present a formidable challenge, but also an opportunity for Indonesia to demonstrate its resilience and capacity for coordinated action. The confluence of a strong El Niño and a potential Positive IOD demands an unprecedented level of preparedness and collaboration across all levels of government, private sector, academic institutions, and civil society.

While the scientific predictions offer a glimpse into a potentially harsh reality, collective vigilance, strategic planning, and adaptive measures can mitigate the worst impacts. The coming months will be a true test of Indonesia’s ability to navigate complex climatic events and safeguard the well-being and prosperity of its people. The call for unified action is clear: Indonesia must prepare now to weather the impending storm of drought and emerge stronger and more resilient in the face of a changing climate.