Severe Air Quality Hits Palangkaraya, Indonesia, in August–September 2026

On 15 August 2026, Palangkaraya recorded an AQI of just 86 — one of the cleaner days this city has seen in years during the dry season. Three weeks later, that figure had ballooned to 240. That single arc — from moderate air to hazardous conditions in under a month — tells you almost everything you need to know about how Palangkaraya's fire and haze season unfolded this year.The 29-day dataset running from 13 August to 10 September 2026 captures one of the most dramatic pollution escalations recorded for this Central Kalimantan city in recent memory, with average AQI sitting at 173.3 and PM2.5 averaging 106 micrograms per cubic metre across the entire period.

For Indian readers tracking cross-border air quality trends in Southeast Asia, Palangkaraya is a familiar name in the annual haze conversation. The city sits in the heart of peatland country — terrain that, when dry and ignited, produces smoke that blankets entire provinces and pushes air quality indices into territory that health authorities classify as dangerous for everyone, not just vulnerable groups. This year's data confirms that the 2026 fire season arrived on schedule and, by early September, had intensified well beyond what the opening days of August suggested.

Trend Snapshot: How the Numbers Moved

DateAQIPM2.5 (µg/m³)PM10 (µg/m³)13 Aug 2026116426215 Aug 202686 (monthly low)283720 Aug 20261669020028 Aug 202619012921430 Aug 202622216424603 Sep 2026240 (monthly peak)18725005 Sep 2026224171282 (PM10 peak)10 Sep 2026196138206

The overall change across the period was stark: AQI rose by 80 points, PM2.5 climbed by 96 µg/m³, and PM10 increased by a striking 144 µg/m³ from start to end. The city did not simply drift upward in a straight line — there were brief dips and partial recoveries — but the dominant direction was relentlessly toward worse air.

Daily AQI trend generated from the air-quality history.

Daily particulate matter trend for PM2.5 and PM10.

The Brief Window of Cleaner Air and Its Rapid Closure

The dataset opens on 13 August with an AQI of 116 and PM2.5 at 42 µg/m³. These figures place the air in the Unhealthy for Sensitive Groups category, but relative to what followed, they represent the period's most breathable conditions. The very next day, 14 August, saw a slight easing to AQI 109. Then came 15 August — the cleanest single day in the entire 29-day window — with AQI dropping to 86, PM2.5 at just 28 µg/m³, and PM10 at 37 µg/m³.

That brief dip almost certainly reflected a temporary meteorological reprieve: wind shifts, localised cloud cover, or a short spell of reduced fire activity. But it lasted precisely one day. By 16 August, the AQI had already climbed back to 116, and PM10 had jumped sharply to 102 µg/m³ — a near-tripling from the previous day's reading. This rapid reversal signals that the underlying fire pressure was already building. The clean-air window on 15 August was not the beginning of an improvement; it was the last breath before a sustained deterioration.

From 17 August onward, the trend line bent decisively upward. AQI crossed 130 on 17 August, hit 153 on 18 August, and reached 164 by 19 August. Within just four days of the monthly low, palangkaraya air quality had shifted from moderate to unhealthy. PM2.5 went from 28 to 86 µg/m³ in that same four-day span — a more than threefold increase that reflects the rapid accumulation of fine smoke particles from peatland and forest fires in the surrounding region.

The August Escalation: A City Swallowed by Smoke

The second half of August tells the story of a city progressively losing its air. From 20 to 22 August, AQI readings hovered between 166 and 174 — firmly in the Unhealthy bracket — with PM10 spiking above 200 µg/m³ on both 20 and 22 August. These coarser particles, which include dust, ash, and larger combustion debris, signal that fires were burning intensely and that smoke columns were reaching the city in thick concentrations.

A brief partial recovery appeared between 23 and 24 August, when AQI eased to 148 and then 130. PM2.5 dropped to 68 and 52 µg/m³ respectively. This was not clean air — 130 on the AQI scale is still classified as unhealthy for sensitive groups — but it represented a temporary lull, possibly linked to wind direction changes or short-term fire suppression activity. The lull did not hold.

By 25 August, the climb resumed. AQI moved to 146, then 164 on 26 August, then 183 on 27 August. The final days of August were the most alarming of the month. On 28 August, AQI reached 190 with PM2.5 at 129 µg/m³. On 29 August, it crossed 200 for the first time — AQI 202, PM2.5 at 144 µg/m³. Then came 30 August: AQI 222, PM2.5 at 164 µg/m³, PM10 at 246 µg/m³. These are Very Unhealthy to Hazardous readings. At these concentrations, health authorities recommend that all residents — not just those with respiratory conditions — avoid outdoor activity entirely.

Interestingly, 31 August showed a notable single-day drop: AQI fell to 169, PM2.5 to 103 µg/m³, PM10 to 130 µg/m³. This kind of sharp single-day relief in the middle of a sustained haze event is often associated with overnight rainfall or a brief wind shift that temporarily disperses smoke. But as the September data shows, it provided no lasting relief for palangkaraya air pollution.

September's Peak: The Worst Days of the Season

September opened with AQI at 156 on the 1st — still unhealthy, but seemingly retreating from August's worst readings. That impression evaporated within 48 hours. On 2 September, AQI climbed back to 175. Then, on 3 September, it hit 240 — the single highest reading in the entire dataset, with PM2.5 at 187 µg/m³ and PM10 at 250 µg/m³. This is deep inside Hazardous territory by any international standard.

What followed was not a swift recovery but a sustained plateau of extreme pollution. On 4 September, AQI remained at 231. On 5 September, it was 224 — but PM10 that day hit its own peak of 282 µg/m³, the highest coarse-particle reading in the entire 29-day window. On 6 September, AQI was 221. On 7 September, it climbed again to 231. On 8 September, it sat at 220.

For six consecutive days — 3 to 8 September — palangkaraya aqi stayed above 220. That kind of sustained hazardous-level exposure is not a spike; it is a public health emergency drawn out over nearly a week. PM2.5 readings across those six days ranged from 164 to 187 µg/m³, levels that cause measurable damage to lung tissue even in healthy adults over short periods of repeated exposure.

Only from 9 September did the numbers begin to ease, with AQI falling to 192 and PM2.5 dropping to 131 µg/m³. By 10 September — the final day in the dataset — AQI stood at 196 and PM2.5 at 138 µg/m³. These are still firmly Unhealthy readings. The city had not recovered; it had merely stepped back from the absolute peak.

What This Data Means for Residents and the Season Ahead

The 29-day arc captured in this dataset is not unusual for Palangkaraya — the city has endured severe haze seasons repeatedly over the past decade, driven by the same combination of peatland drainage, land-clearing fires, and dry-season meteorology. What makes the 2026 data notable is the speed and magnitude of the escalation. Moving from an AQI low of 86 to a peak of 240 in just 19 days, and sustaining readings above 220 for six straight days, reflects conditions that overwhelm routine public health advisories.

For residents, the practical implications are severe. At AQI levels above 200, even brief outdoor exposure can trigger respiratory distress in otherwise healthy individuals. Schools, outdoor markets, and physical labour all become high-risk activities. The PM2.5 averages recorded here — 106 µg/m³ across the full period — are roughly 21 times the World Health Organisation's 24-hour guideline of 15 µg/m³. Even on the dataset's cleanest day, 15 August, PM2.5 at 28 µg/m³ was nearly double that guideline.

The data also underscores a pattern that policymakers in Indonesia and across the region have struggled to break: brief meteorological relief events — like the dips on 15 August and 31 August — do not represent structural improvements in air quality. They are pauses within a season that, without significant fire suppression and land-use reform, will reliably produce weeks of hazardous air each year.

As of 10 September 2026, with AQI still at 196, Palangkaraya's haze season shows no sign of having reached its natural conclusion. The dataset ends mid-trend, with PM2.5 and PM10 both still elevated well beyond safe thresholds. Residents, health workers, and local authorities face weeks more of difficult conditions before the dry season releases its grip on Central Kalimantan.