Air quality data from multiple independent sources across Bali consistently shows PM2.5 levels that exceed World Health Organization guidelines — and the monitoring infrastructure needed to track the problem is failing.
9 live sensors across 4 independent platforms (PurpleAir, AQICN, Airly/Nafas, IQAir) currently report Bali air quality readings. A fifth platform, OpenAQ, lists 4 private AirGradient monitors in Bali but all are offline as of early 2026 — their historical CSVs are still available. As of April 14, 2026, the majority of inland stations read in the Moderate range or worse, with the government's own Badung Sempidi station recording PM2.5 of 38 µg/m³ — exceeding the WHO 2021 24-hour guideline of 15 µg/m³ by over 150%.
469 days of historical data from a community sensor in Kerobokan (Nov 2024 – Mar 2026) show that 68% of recorded days exceeded the WHO 2021 24-hour guideline of 15 µg/m³. The typical daily PM2.5 was 21.9 µg/m³ — 4.4× the WHO 2021 annual guideline of 5 µg/m³.
687 days of data from Klungkung (East Bali, PurpleAir) show a strikingly similar pattern — confirming this is not an isolated, hyperlocal issue but a broader concern across the island.
Meanwhile, Jimbaran on the southern coast consistently records near-zero PM2.5, demonstrating that clean air exists in Bali — the pollution is location-dependent and likely tied to inland burning activity.
Bali's only government air quality station in Denpasar has been offline since August 9, 2025 — over 8 months with no public repair timeline. Its final two readings showed a sharp spike to PM2.5 of 45.7 and 75.0 µg/m³ (classified "Unhealthy") before it went dark.
The station does not appear in search results on the public KLHK portal (ispu.menlhk.go.id) — searches for 'Denpasar,' 'Bali,' or 'Gianyar' return no results, though the station remains in internal listings as 'Sedang dalam perawatan' (under maintenance). Only Kabupaten Badung (Sempidi) is listed in public-facing search results.
The only independent community sensor covering the Kerobokan–Canggu corridor stopped recording on March 15, 2026 — two weeks before a regulation change that has reportedly increased waste burning.
One government sensor now covers the entire island of 4.4 million people. For comparison, Hong Kong (7.5M) operates 18. Bangkok (10.7M) operates approximately 70.
On April 1, 2026, Denpasar banned organic waste from the Suwung landfill. Reports indicate the move — intended to encourage waste separation — has instead driven an increase in waste burning and river dumping, with cleanup crews removing approximately 7 tons of waste from rivers daily, according to local media reporting citing Denpasar's PUPR office. Burning mixed waste releases PM2.5, dioxins, and other toxic compounds.
There is currently no data to measure the air quality impact of this regulation change, because the monitoring infrastructure does not exist.
Live readings from multiple independent sources across Bali. Auto-refreshed approximately hourly from PurpleAir, AQICN, and IQAir APIs.
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The Klungkung sensor — located in East Bali, away from the main waste-affected areas — shows a consistent pattern of moderate baseline pollution with daily spikes reaching the "Unhealthy for Sensitive Groups" range. This pattern is similar to what the historical Kerobokan sensor recorded.
| Date | Daily Avg PM2.5 | Daily Max | Daily Min | EPA Category |
|---|---|---|---|---|
| Apr 7 | 22.3 µg/m³ | 64.8 | 5.0 | Moderate |
| Apr 8 | 30.1 µg/m³ | 87.1 | 10.1 | Moderate |
| Apr 9 | 33.1 µg/m³ | 84.7 | 7.6 | Moderate |
| Apr 10 | 19.7 µg/m³ | 53.2 | 11.6 | Moderate |
| Apr 11 | 25.1 µg/m³ | 51.9 | 13.4 | Moderate |
| Apr 12 | 27.8 µg/m³ | 93.5 | 7.3 | Moderate |
| Apr 13 | 21.9 µg/m³ | 56.8 | 8.1 | Moderate |
Note: Daily max spikes of 50–93 µg/m³ enter the "Unhealthy for Sensitive Groups" range and suggest intermittent pollution events even in areas away from the Denpasar waste corridor. Without more sensors, it is not possible to determine how widespread these events are.
The chart below shows every day of recorded data from the Kerobokan sensor. The blue line shows the daily median; the red line shows the daily maximum spike. Hover for exact values. Background colour bands show US EPA air quality categories.
On April 1, 2026, Denpasar authorities banned organic waste from the Suwung landfill — Bali's largest waste processing site — as part of a plan to close it by August 2026. The regulation's stated goal is a legitimate environmental objective: pushing households toward waste separation and reducing landfill dependency.
However, reports indicate that implementation has outpaced infrastructure. Without adequate composting facilities or collection alternatives in place, some residents have reportedly turned to burning waste or dumping it in waterways. Denpasar cleanup crews were reportedly removing approximately 7 tons of waste from rivers daily, according to the city's Public Works office (PUPR).
Waste burning — especially of mixed waste containing plastics — releases fine particulate matter, dioxins, furans, and other harmful compounds. The concern is not the regulation's intent, but whether adequate monitoring and infrastructure exist to manage the transition safely.
An audit of all publicly accessible air quality platforms (conducted April 13, 2026) reveals significant monitoring gaps:
| Source | Bali Stations | Type | Status |
|---|---|---|---|
| KLHK (Gov) | 1 listed (Badung Sempidi) | Government | Active — O3 only listed |
| Nafas | 4 (Ubud, Denpasar, Sanur, Pemogan) | Private (DBS Indonesia) | Active |
| IQAir | ~10 private contributors | Private citizens/businesses | Active |
| PurpleAir | 2 (Jimbaran, Klungkung) | Community sensors | Active |
| AQICN/GAIA | 1 active (Sempidi) | Government + community | Kerobokan: Offline Mar 15 Denpasar: Offline Aug 2025 |
| OpenAQ / AirGradient | 4 mapped (Ubud, Balangan, 2× Kopernik) | Open data platform + private AirGradient sensors | All offline Last: Aug 2025 – Mar 2026 |
| Sensor.Community | 0 | Open source community | No coverage |
The Denpasar government station (KLHK, located at Graha Sewaka Dharma, Lumintang) went offline on August 9, 2025. It is listed on the KLHK portal as "Sedang dalam perawatan" (under maintenance). However, a search of the KLHK station list at ispu.menlhk.go.id returns no results for "Denpasar," "Bali," or "Gianyar" — only Kabupaten Badung is listed.
The Kerobokan community sensor (GAIA network) stopped recording on March 15, 2026. As a privately owned community device, it may have simply failed or been taken offline by its operator. The reason for the outage is unknown.
The systemic issue is that Bali does not have adequate air quality monitoring infrastructure for an island of its size and importance.
| Comparison | Government AQ Stations | Population | Stations per million |
|---|---|---|---|
| Bali (current) | 1 | 4.4 million | 0.2 |
| Hong Kong | 18 | 7.5 million | 2.4 |
| Bangkok (Thailand) | ~70 | 10.7 million | 6.5 |
| London (UK) | 100+ | 9.0 million | 11+ |
PM2.5 refers to fine particulate matter smaller than 2.5 micrometers — small enough to penetrate deep into the lungs and enter the bloodstream. Long-term exposure is linked to respiratory and cardiovascular disease. When waste containing plastics is burned, the smoke contains additional toxic compounds (dioxins, furans) that standard PM sensors do not measure.
| Standard | PM2.5 Level | Classification |
|---|---|---|
| WHO 2021 Guideline (Annual) | 5 µg/m³ | Recommended long-term target |
| WHO 2021 Guideline (24-hour) | 15 µg/m³ | Recommended daily exposure limit |
| WHO Interim Target 4 (IT-4) | Annual 10 / 24-hour 25 µg/m³ | Transitional benchmark used by many countries |
| US EPA "Good" | 0–9.0 µg/m³ | Satisfactory |
| US EPA "Moderate" | 9.1–35.4 µg/m³ | Acceptable; concern for sensitive groups |
| US EPA "Unhealthy Sensitive" | 35.5–55.4 µg/m³ | At-risk groups affected |
| US EPA "Unhealthy" | 55.5–125.4 µg/m³ | Everyone may be affected |
| US EPA "Very Unhealthy" | 125.5–225.4 µg/m³ | Health alert |
| US EPA "Hazardous" | 225.5+ µg/m³ | Emergency conditions |
Historical air quality data for Bali is limited but not absent. Publicly downloadable records exist for five monitors on two networks:
The active Badung Sempidi (AQICN) station does not provide downloadable historical data. The PurpleAir sensors in Klungkung and Jimbaran are still reporting — see the live monitor for their full histories.
The Denpasar KLHK station recorded 548 days of data from September 2023 to August 2025. The average daily median was 15.1 µg/m³ — 3.0× the WHO 2021 annual guideline of 5 µg/m³. Approximately 40% of days exceeded the WHO 2021 24-hour guideline of 15 µg/m³.
Notably, the station's final two recordings showed a sharp spike — daily medians of 45.7 and 75.0 µg/m³ on August 8–9, 2025 — before going offline. The station has been offline for 8+ months with no public repair timeline.
Note: This data comes from a government-operated station in central Denpasar, representing urban conditions.
The Kerobokan sensor recorded 469 days of data from November 2024 to March 2026. The average daily median was 21.9 µg/m³ — 4.4 times the WHO 2021 annual guideline of 5 µg/m³. 68% of days exceeded the WHO 2021 24-hour guideline of 15 µg/m³. Monthly averages ranged from 7.1 to 32.7 µg/m³ depending on the month.
Located in a residential area near Canggu, this sensor may be closer to burning sources than the central Denpasar station. During the 166-day overlap period with the Denpasar station, Kerobokan readings were consistently 1.1–1.7 times higher — suggesting localised variation in air quality even within south Bali.
A monthly pattern showed higher readings from February through October and lower readings from November through March, but this cannot be confirmed as seasonal without more data points from additional years and locations.
Three private AirGradient units — surfaced via the OpenAQ platform — provide short but useful windows into 2025. None overlap with the AQICN sensors, so they mostly fill geographic gaps rather than allow cross-validation.
Many OpenAQ-listed Indonesian monitors are offline — this is common for community sensor networks and not unusual, not a controversy. Historical CSVs remain downloadable via the OpenAQ Explorer even when the live data stops.
Even with these five historical records, coverage is thin: the longest dataset (Kerobokan) covers about 15 months; the shortest (Balangan) under a month. There is still no multi-year record for Sanur, North Bali, or East Bali. The Klungkung PurpleAir sensor in East Bali currently shows moderate patterns but has limited comparable history.
Without distributed monitoring, it is impossible to determine whether the patterns above are representative of Bali as a whole, or how they track regulatory changes such as the April 2026 waste rules. More sensors, in more locations, recording over longer periods are needed to build a meaningful picture of the island's air quality.
All data in this document comes from publicly accessible sources. We encourage independent verification: