SmogRank / Laos / Vientiane Prefecture

Air quality in Vientiane

Vientiane Prefecture, Laos. PM2.5 from 7 low-cost sensors, updated hourly.

31.4µg/m³
Moderate

Latest hour (19:00 UTC), 2.1× the WHO 24-hour guideline. 24-hour average 25.3 µg/m³.

Rank among 1,174 cities

24 hours#42of 1,174, at 25.3 µg/m³
7 days#364of 2,314, at 11.5 µg/m³
30 days#187of 2,322, at 18.2 µg/m³
This year#77of 2,173, at 36.4 µg/m³

Why it ranks here

Cleaner than usual. The last 7 days averaged 11.5 µg/m³, well below its typical 27.9; rain or wind often clears the air for a while.
Seasonal. Over the past year its worst months were April, averaging up to 95.1 µg/m³ against 8.9 in its cleanest month. Seasonal peaks usually come from heating, crop burning, fire or dust seasons.

Based on Vientiane's own measurements; causes are the usual kinds for a pattern like this, not a confirmed source.

The last 12 months, day by day

1102031Nov 2025DecJan 2026FebMarAprMayJunJulAugSepOct2025-11-01: 8.5 µg/m³2025-11-02: 10.9 µg/m³2025-11-03: 6.2 µg/m³2025-11-04: 11.1 µg/m³2025-11-05: 18.4 µg/m³2025-11-06: 48.6 µg/m³2025-11-07: 27.1 µg/m³2025-11-08: 5.1 µg/m³2025-11-09: 15.8 µg/m³2025-11-10: 21.6 µg/m³2025-11-11: 33.3 µg/m³2025-11-12: 31.0 µg/m³2025-11-13: 25.9 µg/m³2025-11-14: no data2025-11-15: 38.2 µg/m³2025-11-16: 28.9 µg/m³2025-11-17: 33.2 µg/m³2025-11-18: 29.0 µg/m³2025-11-19: 13.0 µg/m³2025-11-20: 21.1 µg/m³2025-11-21: 26.6 µg/m³2025-11-22: 49.3 µg/m³2025-11-23: 47.2 µg/m³2025-11-24: 50.3 µg/m³2025-11-25: 46.6 µg/m³2025-11-26: 54.6 µg/m³2025-11-27: 41.3 µg/m³2025-11-28: 64.2 µg/m³2025-11-29: 69.4 µg/m³2025-11-30: 44.8 µg/m³2025-12-01: 44.4 µg/m³2025-12-02: 43.9 µg/m³2025-12-03: 42.5 µg/m³2025-12-04: 52.2 µg/m³2025-12-05: 42.6 µg/m³2025-12-06: 40.3 µg/m³2025-12-07: 51.5 µg/m³2025-12-08: 37.2 µg/m³2025-12-09: 56.4 µg/m³2025-12-10: 54.6 µg/m³2025-12-11: 42.9 µg/m³2025-12-12: 37.9 µg/m³2025-12-13: 17.1 µg/m³2025-12-14: 5.8 µg/m³2025-12-15: 28.4 µg/m³2025-12-16: 46.2 µg/m³2025-12-17: 37.8 µg/m³2025-12-18: 38.9 µg/m³2025-12-19: 56.5 µg/m³2025-12-20: 65.9 µg/m³2025-12-21: 36.9 µg/m³2025-12-22: 37.8 µg/m³2025-12-23: 53.0 µg/m³2025-12-24: 52.1 µg/m³2025-12-25: 32.6 µg/m³2025-12-26: 30.6 µg/m³2025-12-27: 49.0 µg/m³2025-12-28: 49.0 µg/m³2025-12-29: 68.0 µg/m³2025-12-30: 76.4 µg/m³2025-12-31: 77.2 µg/m³2026-01-01: 72.0 µg/m³2026-01-02: 36.5 µg/m³2026-01-03: 29.5 µg/m³2026-01-04: 37.1 µg/m³2026-01-05: 51.3 µg/m³2026-01-06: 27.3 µg/m³2026-01-07: 26.6 µg/m³2026-01-08: 44.2 µg/m³2026-01-09: 65.0 µg/m³2026-01-10: 76.6 µg/m³2026-01-11: 74.7 µg/m³2026-01-12: 96.4 µg/m³2026-01-13: 91.6 µg/m³2026-01-14: 92.2 µg/m³2026-01-15: 92.2 µg/m³2026-01-16: 85.0 µg/m³2026-01-17: 71.3 µg/m³2026-01-18: 65.1 µg/m³2026-01-19: 56.6 µg/m³2026-01-20: 64.0 µg/m³2026-01-21: 64.1 µg/m³2026-01-22: 38.6 µg/m³2026-01-23: 30.4 µg/m³2026-01-24: 40.3 µg/m³2026-01-25: 54.8 µg/m³2026-01-26: 67.0 µg/m³2026-01-27: 60.8 µg/m³2026-01-28: 55.5 µg/m³2026-01-29: 57.2 µg/m³2026-01-30: 68.5 µg/m³2026-01-31: 60.9 µg/m³2026-02-01: 46.0 µg/m³2026-02-02: 30.9 µg/m³2026-02-03: 34.5 µg/m³2026-02-04: 57.8 µg/m³2026-02-05: 57.5 µg/m³2026-02-06: 57.4 µg/m³2026-02-07: 58.0 µg/m³2026-02-08: 32.3 µg/m³2026-02-09: 23.7 µg/m³2026-02-10: 50.3 µg/m³2026-02-11: 59.3 µg/m³2026-02-12: 40.2 µg/m³2026-02-13: 49.6 µg/m³2026-02-14: 55.7 µg/m³2026-02-15: 58.9 µg/m³2026-02-16: 65.3 µg/m³2026-02-17: 41.3 µg/m³2026-02-18: 24.4 µg/m³2026-02-19: 17.3 µg/m³2026-02-20: 26.5 µg/m³2026-02-21: 50.2 µg/m³2026-02-22: 75.5 µg/m³2026-02-23: 72.6 µg/m³2026-02-24: 51.7 µg/m³2026-02-25: 32.6 µg/m³2026-02-26: 32.2 µg/m³2026-02-27: 32.7 µg/m³2026-02-28: 37.2 µg/m³2026-03-01: 55.0 µg/m³2026-03-02: 52.7 µg/m³2026-03-03: 69.2 µg/m³2026-03-04: 49.5 µg/m³2026-03-05: 29.3 µg/m³2026-03-06: 30.9 µg/m³2026-03-07: 24.8 µg/m³2026-03-08: 27.9 µg/m³2026-03-09: 32.4 µg/m³2026-03-10: 16.3 µg/m³2026-03-11: 45.1 µg/m³2026-03-12: 33.1 µg/m³2026-03-13: 46.8 µg/m³2026-03-14: 34.1 µg/m³2026-03-15: 29.4 µg/m³2026-03-16: 39.5 µg/m³2026-03-17: 48.9 µg/m³2026-03-18: 54.2 µg/m³2026-03-19: 57.4 µg/m³2026-03-20: 49.2 µg/m³2026-03-21: 47.3 µg/m³2026-03-22: 52.3 µg/m³2026-03-23: 60.0 µg/m³2026-03-24: 67.3 µg/m³2026-03-25: 50.8 µg/m³2026-03-26: 56.3 µg/m³2026-03-27: 85.5 µg/m³2026-03-28: 79.0 µg/m³2026-03-29: 62.7 µg/m³2026-03-30: 75.9 µg/m³2026-03-31: 103.0 µg/m³2026-04-01: 138.0 µg/m³2026-04-02: 118.0 µg/m³2026-04-03: 108.0 µg/m³2026-04-04: 146.0 µg/m³2026-04-05: 168.0 µg/m³2026-04-06: 153.0 µg/m³2026-04-07: 129.0 µg/m³2026-04-08: 100.0 µg/m³2026-04-09: 98.1 µg/m³2026-04-10: 94.6 µg/m³2026-04-11: 91.0 µg/m³2026-04-12: 104.0 µg/m³2026-04-13: 157.0 µg/m³2026-04-14: 141.0 µg/m³2026-04-15: 123.0 µg/m³2026-04-16: 145.0 µg/m³2026-04-17: 161.0 µg/m³2026-04-18: 82.7 µg/m³2026-04-19: 62.6 µg/m³2026-04-20: 52.1 µg/m³2026-04-21: 68.2 µg/m³2026-04-22: 79.7 µg/m³2026-04-23: 77.4 µg/m³2026-04-24: 34.0 µg/m³2026-04-25: 32.0 µg/m³2026-04-26: 36.5 µg/m³2026-04-27: 45.4 µg/m³2026-04-28: 42.1 µg/m³2026-04-29: 33.1 µg/m³2026-04-30: 33.8 µg/m³2026-05-01: 38.6 µg/m³2026-05-02: 24.0 µg/m³2026-05-03: 40.7 µg/m³2026-05-04: 27.7 µg/m³2026-05-05: 17.1 µg/m³2026-05-06: 28.1 µg/m³2026-05-07: 46.7 µg/m³2026-05-08: 27.8 µg/m³2026-05-09: 31.9 µg/m³2026-05-10: 18.8 µg/m³2026-05-11: 34.9 µg/m³2026-05-12: 35.2 µg/m³2026-05-13: 24.2 µg/m³2026-05-14: 17.5 µg/m³2026-05-15: 19.9 µg/m³2026-05-16: 15.4 µg/m³2026-05-17: 14.8 µg/m³2026-05-18: 14.5 µg/m³2026-05-19: 3.4 µg/m³2026-05-20: 7.7 µg/m³2026-05-21: 12.7 µg/m³2026-05-22: 18.9 µg/m³2026-05-23: 16.6 µg/m³2026-05-24: 16.2 µg/m³2026-05-25: 13.2 µg/m³2026-05-26: 10.4 µg/m³2026-05-27: 15.3 µg/m³2026-05-28: 20.2 µg/m³2026-05-29: 15.6 µg/m³2026-05-30: 22.0 µg/m³2026-05-31: 24.8 µg/m³2026-06-01: 35.7 µg/m³2026-06-02: 42.5 µg/m³2026-06-03: 39.5 µg/m³2026-06-04: 25.7 µg/m³2026-06-05: 8.5 µg/m³2026-06-06: 13.0 µg/m³2026-06-07: 19.0 µg/m³2026-06-08: 10.0 µg/m³2026-06-09: 10.5 µg/m³2026-06-10: 11.9 µg/m³2026-06-11: 5.0 µg/m³2026-06-12: 20.4 µg/m³2026-06-13: 12.0 µg/m³2026-06-14: 12.8 µg/m³2026-06-15: 4.3 µg/m³2026-06-16: 7.1 µg/m³2026-06-17: 12.5 µg/m³2026-06-18: 13.7 µg/m³2026-06-19: 12.7 µg/m³2026-06-20: 15.2 µg/m³2026-06-21: 15.4 µg/m³2026-06-22: 15.5 µg/m³2026-06-23: 12.3 µg/m³2026-06-24: 14.1 µg/m³2026-06-25: 9.7 µg/m³2026-06-26: 15.3 µg/m³2026-06-27: 17.4 µg/m³2026-06-28: 14.7 µg/m³2026-06-29: 17.1 µg/m³2026-06-30: 5.1 µg/m³2026-07-01: 8.4 µg/m³2026-07-02: 11.4 µg/m³2026-07-03: 19.6 µg/m³2026-07-04: 7.5 µg/m³2026-07-05: 9.3 µg/m³2026-07-06: 6.3 µg/m³2026-07-07: 11.5 µg/m³2026-07-08: 10.0 µg/m³2026-07-09: 12.8 µg/m³2026-07-10: 9.4 µg/m³2026-07-11: 13.0 µg/m³2026-07-12: 20.1 µg/m³2026-07-13: 13.9 µg/m³2026-07-14: 18.1 µg/m³2026-07-15: 10.8 µg/m³2026-07-16: 15.1 µg/m³2026-07-17: 20.8 µg/m³2026-07-18: 22.3 µg/m³2026-07-19: 27.1 µg/m³2026-07-20: 25.7 µg/m³2026-07-21: 11.5 µg/m³2026-07-22: 8.6 µg/m³2026-07-23: 16.0 µg/m³2026-07-24: 23.2 µg/m³2026-07-25: 9.3 µg/m³2026-07-26: 16.7 µg/m³2026-07-27: 8.7 µg/m³2026-07-28: 17.2 µg/m³2026-07-29: 10.6 µg/m³2026-07-30: 13.7 µg/m³2026-07-31: 7.7 µg/m³2026-08-01: 4.9 µg/m³2026-08-02: 7.9 µg/m³2026-08-03: 7.0 µg/m³2026-08-04: 11.0 µg/m³2026-08-05: 7.0 µg/m³2026-08-06: 7.9 µg/m³2026-08-07: 16.2 µg/m³2026-08-08: 6.7 µg/m³2026-08-09: 8.7 µg/m³2026-08-10: 4.0 µg/m³2026-08-11: 5.0 µg/m³2026-08-12: 7.9 µg/m³2026-08-13: 6.6 µg/m³2026-08-14: 9.8 µg/m³2026-08-15: 9.5 µg/m³2026-08-16: 7.4 µg/m³2026-08-17: 5.3 µg/m³2026-08-18: 12.4 µg/m³2026-08-19: 7.8 µg/m³2026-08-20: 3.8 µg/m³2026-08-21: 3.0 µg/m³2026-08-22: 6.6 µg/m³2026-08-23: 5.9 µg/m³2026-08-24: 16.6 µg/m³2026-08-25: 20.3 µg/m³2026-08-26: 9.8 µg/m³2026-08-27: 12.8 µg/m³2026-08-28: 12.0 µg/m³2026-08-29: 12.6 µg/m³2026-08-30: 13.3 µg/m³2026-08-31: 7.1 µg/m³2026-09-01: 8.1 µg/m³2026-09-02: 18.8 µg/m³2026-09-03: 18.0 µg/m³2026-09-04: 15.7 µg/m³2026-09-05: 24.3 µg/m³2026-09-06: 12.4 µg/m³2026-09-07: 13.1 µg/m³2026-09-08: 15.0 µg/m³2026-09-09: 7.0 µg/m³2026-09-10: 16.9 µg/m³2026-09-11: 27.2 µg/m³2026-09-12: 33.1 µg/m³2026-09-13: 37.3 µg/m³2026-09-14: 30.3 µg/m³2026-09-15: 4.4 µg/m³2026-09-16: 7.9 µg/m³2026-09-17: 12.5 µg/m³2026-09-18: 13.6 µg/m³2026-09-19: 11.4 µg/m³2026-09-20: 15.7 µg/m³2026-09-21: 18.5 µg/m³2026-09-22: 42.4 µg/m³2026-09-23: 39.4 µg/m³2026-09-24: 24.3 µg/m³2026-09-25: 7.1 µg/m³2026-09-26: 2.0 µg/m³2026-09-27: 4.1 µg/m³2026-09-28: 8.1 µg/m³2026-09-29: 16.4 µg/m³2026-09-30: 31.6 µg/m³2026-10-01: no data
262 of 363 measured days were over the WHO 24-hour guideline (15 µg/m³). One row per month, one square per local day.
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

Last 4 days, hour by hour

15502026-10-01 00:00 UTC: 36.3 µg/m³2026-10-01 01:00 UTC: 27.6 µg/m³2026-10-01 02:00 UTC: 23.0 µg/m³2026-10-01 03:00 UTC: 17.8 µg/m³2026-10-01 04:00 UTC: 12.1 µg/m³2026-10-01 05:00 UTC: 7.5 µg/m³2026-10-01 06:00 UTC: 8.5 µg/m³2026-10-01 07:00 UTC: 8.2 µg/m³2026-10-01 08:00 UTC: 8.1 µg/m³2026-10-01 09:00 UTC: 8.3 µg/m³2026-10-01 10:00 UTC: 15.9 µg/m³2026-10-01 12:00 UTC: 37.0 µg/m³2026-10-01 13:00 UTC: 50.1 µg/m³2026-10-01 14:00 UTC: 45.3 µg/m³2026-10-01 15:00 UTC: 42.0 µg/m³2026-10-01 16:00 UTC: 33.0 µg/m³2026-10-01 17:00 UTC: 29.1 µg/m³2026-10-01 18:00 UTC: 39.2 µg/m³2026-10-01 19:00 UTC: 31.4 µg/m³Sep 28Sep 29Sep 30Oct 1
Times in UTC. Dashed line: WHO 24-hour guideline (15 µg/m³).

Its world rank, day by day

#1#2340NovDecJanFebMarAprMayJunJulAugSep
Rank on each day's board (1 = most polluted city that day).

2026 against 2025, month by month

15Jan 2026: 59.8 µg/m³JanFeb 2026: 45.4 µg/m³FebMar 2025: 85.1 µg/m³Mar 2026: 50.5 µg/m³MarApr 2025: 45.0 µg/m³Apr 2026: 95.1 µg/m³AprMay 2025: 20.9 µg/m³May 2026: 21.8 µg/m³MayJun 2025: 15.1 µg/m³Jun 2026: 15.6 µg/m³JunJul 2025: 9.0 µg/m³Jul 2026: 14.1 µg/m³JulAug 2025: 15.1 µg/m³Aug 2026: 8.9 µg/m³AugSep 2025: 12.6 µg/m³Sep 2026: 17.9 µg/m³SepOct 2025: 20.9 µg/m³OctNov 2025: 31.8 µg/m³NovDec 2025: 45.3 µg/m³Dec
Faded bars: 2025. A month shows once it has 10 measured days.

This week against past years

This weekThis week: 11.5 µg/m³11.520252025: 8.4 µg/m³8.4
Mean PM2.5 for 25 Sept to 1 Oct in each year. Dashed line: WHO 24-hour guideline.

Monitors

StationOperatorType
Chomphet Secondary School - Sisattanak, Vientiane Capital ມັດທະຍົມສົມບູນ ຈອມເພັດCC BY 4.0UNICEFLow-cost
Chansavang Secondary School - Sikhottabong, Vientiane Capital ມັດທະຍົມ ຈັນສະຫວ່າງCC BY 4.0UNICEFLow-cost
Sathit Secondary School - Xaythani, Vientiane Capital ມັດທະຍົມ ສາທິດCC BY 4.0UNICEFLow-cost
UNICEF Lao PDR COCC BY 4.0UNICEFLow-cost
ໂຮງໝໍມະໂຫສົດ Mahosot HospitalCC BY 4.0UNICEFLow-cost
ບ້ານສະພານທອງໃຕ້ Saphanthong VillageCC BY 4.0UNICEFLow-cost
Tata's AirGradient GoCC BY 4.0AirGradientLow-cost

No reference monitor here, so the value is the median of low-cost sensors (at least two reporting each hour). Low-cost sensors can read high in humid air. Data via OpenAQ; licences as listed. How we rank. Embed this on your site.

Updated 2026-10-01 20:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.