SmogRank / Japan / Miyazaki

Air quality in Kobayashi

Miyazaki, Japan. PM2.5 from 1 reference monitor, updated hourly.

9.5 µg/m³
Moderate

Mean for 30 Sept, the most recent day with readings, 0.6× the WHO 24-hour guideline. No hourly readings have reached us since; some networks publish days late.

Rank

24 h
–
not enough data
7 days
#254
of 2,333 · 14.5 µg/m³
30 days
#474
of 2,331 · 9.1 µg/m³
Year
#967
of 2,173 · 9.0 µg/m³

Why it ranks here

Likely volcanic emissions. On Sep 25, when Kobayashi averaged 22.7 µg/m³ (its typical day: 7.9), the Tokyo Volcanic Ash Advisory Centre issued 6 ash advisories for Sakurajima (Aira Caldera), 53 km away, with ash seen in satellite images. Volcanic gas and ash are a likely contributor; we don't check which way the wind blew, and advisories track ash for aircraft, often well above the ground.

Based on Kobayashi's own measurements, with volcanic ash advisories from the Tokyo (JMA) and Washington (NOAA) VAACs; causes are the usual kinds for a pattern like this, not a confirmed source.

Hour by hour

No hourly readings in the last few days. The chart returns when the monitors' data arrives.

Every day for a year

SepNovDecJanFebMarAprMayJunJulAugSepMonWedFri2025-09-29: 6.1 µg/m³2025-09-30: 10.3 µg/m³2025-10-01: 11.6 µg/m³2025-10-02: 14.3 µg/m³2025-10-03: 13.9 µg/m³2025-10-04: 10.8 µg/m³2025-10-05: 8.6 µg/m³2025-10-06: 9.2 µg/m³2025-10-07: 12.0 µg/m³2025-10-08: 8.4 µg/m³2025-10-09: 11.6 µg/m³2025-10-10: 9.4 µg/m³2025-10-11: 6.0 µg/m³2025-10-12: 7.1 µg/m³2025-10-13: 14.0 µg/m³2025-10-14: 14.4 µg/m³2025-10-15: no data2025-10-16: no data2025-10-17: no data2025-10-18: no data2025-10-19: no data2025-10-20: no data2025-10-21: 7.8 µg/m³2025-10-22: 5.3 µg/m³2025-10-23: 4.8 µg/m³2025-10-24: 6.3 µg/m³2025-10-25: 5.1 µg/m³2025-10-26: 7.2 µg/m³2025-10-27: no data2025-10-28: no data2025-10-29: 8.3 µg/m³2025-10-30: 7.4 µg/m³2025-10-31: 5.3 µg/m³2025-11-01: 7.1 µg/m³2025-11-02: 8.8 µg/m³2025-11-03: 5.1 µg/m³2025-11-04: 7.0 µg/m³2025-11-05: 6.3 µg/m³2025-11-06: 5.7 µg/m³2025-11-07: 9.2 µg/m³2025-11-08: 10.1 µg/m³2025-11-09: 6.5 µg/m³2025-11-10: 12.9 µg/m³2025-11-11: 12.0 µg/m³2025-11-12: 12.8 µg/m³2025-11-13: 4.0 µg/m³2025-11-14: no data2025-11-15: no data2025-11-16: no data2025-11-17: no data2025-11-18: no data2025-11-19: no data2025-11-20: no data2025-11-21: no data2025-11-22: no data2025-11-23: no data2025-11-24: no data2025-11-25: no data2025-11-26: 11.9 µg/m³2025-11-27: 11.8 µg/m³2025-11-28: 12.2 µg/m³2025-11-29: 13.8 µg/m³2025-11-30: 14.5 µg/m³2025-12-01: 8.1 µg/m³2025-12-02: 10.7 µg/m³2025-12-03: 9.0 µg/m³2025-12-04: 4.6 µg/m³2025-12-05: 6.1 µg/m³2025-12-06: 7.1 µg/m³2025-12-07: 6.0 µg/m³2025-12-08: 12.3 µg/m³2025-12-09: 8.5 µg/m³2025-12-10: 7.1 µg/m³2025-12-11: 10.1 µg/m³2025-12-12: 8.2 µg/m³2025-12-13: 8.6 µg/m³2025-12-14: 4.6 µg/m³2025-12-15: 5.4 µg/m³2025-12-16: 6.4 µg/m³2025-12-17: 8.9 µg/m³2025-12-18: 11.9 µg/m³2025-12-19: 7.7 µg/m³2025-12-20: 8.2 µg/m³2025-12-21: 7.7 µg/m³2025-12-22: 4.5 µg/m³2025-12-23: 4.9 µg/m³2025-12-24: 6.6 µg/m³2025-12-25: 3.5 µg/m³2025-12-26: 4.3 µg/m³2025-12-27: 4.6 µg/m³2025-12-28: 7.4 µg/m³2025-12-29: 9.7 µg/m³2025-12-30: 10.5 µg/m³2025-12-31: 10.1 µg/m³2026-01-01: 3.6 µg/m³2026-01-02: 4.2 µg/m³2026-01-03: 4.4 µg/m³2026-01-04: 7.9 µg/m³2026-01-05: 8.1 µg/m³2026-01-06: 5.7 µg/m³2026-01-07: 8.3 µg/m³2026-01-08: 9.5 µg/m³2026-01-09: 4.7 µg/m³2026-01-10: 6.4 µg/m³2026-01-11: 4.0 µg/m³2026-01-12: 6.1 µg/m³2026-01-13: 8.7 µg/m³2026-01-14: 8.6 µg/m³2026-01-15: 13.7 µg/m³2026-01-16: 11.6 µg/m³2026-01-17: 11.0 µg/m³2026-01-18: 17.1 µg/m³2026-01-19: no data2026-01-20: 12.7 µg/m³2026-01-21: 3.4 µg/m³2026-01-22: 3.3 µg/m³2026-01-23: 6.2 µg/m³2026-01-24: no data2026-01-25: no data2026-01-26: 7.4 µg/m³2026-01-27: 10.7 µg/m³2026-01-28: 7.8 µg/m³2026-01-29: no data2026-01-30: 10.8 µg/m³2026-01-31: 3.5 µg/m³2026-02-01: 12.0 µg/m³2026-02-02: 12.2 µg/m³2026-02-03: 8.3 µg/m³2026-02-04: 4.8 µg/m³2026-02-05: 7.0 µg/m³2026-02-06: 9.1 µg/m³2026-02-07: 10.1 µg/m³2026-02-08: no data2026-02-09: 7.0 µg/m³2026-02-10: 11.2 µg/m³2026-02-11: 3.7 µg/m³2026-02-12: 11.5 µg/m³2026-02-13: 9.8 µg/m³2026-02-14: 10.4 µg/m³2026-02-15: 8.1 µg/m³2026-02-16: 18.2 µg/m³2026-02-17: 15.7 µg/m³2026-02-18: 5.5 µg/m³2026-02-19: 15.4 µg/m³2026-02-20: 7.9 µg/m³2026-02-21: 11.8 µg/m³2026-02-22: 11.8 µg/m³2026-02-23: 25.0 µg/m³2026-02-24: 14.6 µg/m³2026-02-25: 4.4 µg/m³2026-02-26: 5.1 µg/m³2026-02-27: 3.4 µg/m³2026-02-28: 5.9 µg/m³2026-03-01: 8.6 µg/m³2026-03-02: 6.1 µg/m³2026-03-03: 2.2 µg/m³2026-03-04: 5.3 µg/m³2026-03-05: 7.8 µg/m³2026-03-06: 6.9 µg/m³2026-03-07: 11.0 µg/m³2026-03-08: 8.5 µg/m³2026-03-09: 8.1 µg/m³2026-03-10: 14.6 µg/m³2026-03-11: 14.3 µg/m³2026-03-12: 12.9 µg/m³2026-03-13: 5.7 µg/m³2026-03-14: 4.6 µg/m³2026-03-15: 6.1 µg/m³2026-03-16: 13.0 µg/m³2026-03-17: 17.7 µg/m³2026-03-18: 21.0 µg/m³2026-03-19: 5.1 µg/m³2026-03-20: 12.8 µg/m³2026-03-21: 11.7 µg/m³2026-03-22: 8.9 µg/m³2026-03-23: 3.7 µg/m³2026-03-24: 10.7 µg/m³2026-03-25: 3.5 µg/m³2026-03-26: 5.2 µg/m³2026-03-27: 10.7 µg/m³2026-03-28: 28.7 µg/m³2026-03-29: 26.9 µg/m³2026-03-30: 12.9 µg/m³2026-03-31: 6.5 µg/m³2026-04-01: 4.0 µg/m³2026-04-02: 10.5 µg/m³2026-04-03: 10.7 µg/m³2026-04-04: 6.5 µg/m³2026-04-05: 11.1 µg/m³2026-04-06: 16.8 µg/m³2026-04-07: 9.1 µg/m³2026-04-08: 7.6 µg/m³2026-04-09: 8.8 µg/m³2026-04-10: 7.4 µg/m³2026-04-11: 10.7 µg/m³2026-04-12: 10.0 µg/m³2026-04-13: 6.2 µg/m³2026-04-14: 4.7 µg/m³2026-04-15: 2.3 µg/m³2026-04-16: 7.0 µg/m³2026-04-17: 9.4 µg/m³2026-04-18: 8.6 µg/m³2026-04-19: 6.5 µg/m³2026-04-20: 5.3 µg/m³2026-04-21: 8.9 µg/m³2026-04-22: 8.9 µg/m³2026-04-23: 4.1 µg/m³2026-04-24: 2.3 µg/m³2026-04-25: 4.1 µg/m³2026-04-26: 3.5 µg/m³2026-04-27: 8.0 µg/m³2026-04-28: 11.0 µg/m³2026-04-29: 12.2 µg/m³2026-04-30: 5.7 µg/m³2026-05-01: 11.1 µg/m³2026-05-02: 15.5 µg/m³2026-05-03: 13.2 µg/m³2026-05-04: 7.9 µg/m³2026-05-05: 8.3 µg/m³2026-05-06: 7.8 µg/m³2026-05-07: 10.8 µg/m³2026-05-08: 9.0 µg/m³2026-05-09: 7.6 µg/m³2026-05-10: 8.4 µg/m³2026-05-11: 6.1 µg/m³2026-05-12: 6.3 µg/m³2026-05-13: 5.4 µg/m³2026-05-14: 8.6 µg/m³2026-05-15: 10.6 µg/m³2026-05-16: 11.0 µg/m³2026-05-17: 14.4 µg/m³2026-05-18: 14.3 µg/m³2026-05-19: 9.5 µg/m³2026-05-20: 3.8 µg/m³2026-05-21: 5.6 µg/m³2026-05-22: 10.3 µg/m³2026-05-23: 9.1 µg/m³2026-05-24: 4.1 µg/m³2026-05-25: 5.6 µg/m³2026-05-26: 2.8 µg/m³2026-05-27: 2.5 µg/m³2026-05-28: 3.1 µg/m³2026-05-29: 9.8 µg/m³2026-05-30: 14.1 µg/m³2026-05-31: 15.9 µg/m³2026-06-01: 7.4 µg/m³2026-06-02: 1.3 µg/m³2026-06-03: 4.3 µg/m³2026-06-04: 4.6 µg/m³2026-06-05: 5.2 µg/m³2026-06-06: 6.4 µg/m³2026-06-07: 1.6 µg/m³2026-06-08: 11.1 µg/m³2026-06-09: 5.1 µg/m³2026-06-10: 7.7 µg/m³2026-06-11: 11.9 µg/m³2026-06-12: 7.1 µg/m³2026-06-13: 10.9 µg/m³2026-06-14: 9.8 µg/m³2026-06-15: 4.1 µg/m³2026-06-16: 3.4 µg/m³2026-06-17: 1.7 µg/m³2026-06-18: 5.1 µg/m³2026-06-19: 4.0 µg/m³2026-06-20: 8.4 µg/m³2026-06-21: 4.6 µg/m³2026-06-22: 10.7 µg/m³2026-06-23: 2.6 µg/m³2026-06-24: 2.6 µg/m³2026-06-25: 10.0 µg/m³2026-06-26: 6.5 µg/m³2026-06-27: 6.1 µg/m³2026-06-28: 6.2 µg/m³2026-06-29: 11.5 µg/m³2026-06-30: 13.2 µg/m³2026-07-01: 8.0 µg/m³2026-07-02: 3.1 µg/m³2026-07-03: 5.6 µg/m³2026-07-04: 5.7 µg/m³2026-07-05: 6.6 µg/m³2026-07-06: 6.1 µg/m³2026-07-07: 8.9 µg/m³2026-07-08: 5.2 µg/m³2026-07-09: 5.1 µg/m³2026-07-10: 4.6 µg/m³2026-07-11: 4.7 µg/m³2026-07-12: 9.0 µg/m³2026-07-13: 13.6 µg/m³2026-07-14: 9.0 µg/m³2026-07-15: 8.2 µg/m³2026-07-16: 8.2 µg/m³2026-07-17: 10.4 µg/m³2026-07-18: 18.7 µg/m³2026-07-19: 17.4 µg/m³2026-07-20: 19.7 µg/m³2026-07-21: 31.9 µg/m³2026-07-22: 27.2 µg/m³2026-07-23: 19.4 µg/m³2026-07-24: 24.5 µg/m³2026-07-25: 33.5 µg/m³2026-07-26: 17.9 µg/m³2026-07-27: 24.0 µg/m³2026-07-28: 18.5 µg/m³2026-07-29: 7.1 µg/m³2026-07-30: 7.5 µg/m³2026-07-31: 7.1 µg/m³2026-08-01: 9.8 µg/m³2026-08-02: 16.5 µg/m³2026-08-03: 18.1 µg/m³2026-08-04: 10.4 µg/m³2026-08-05: 6.0 µg/m³2026-08-06: 6.0 µg/m³2026-08-07: 6.9 µg/m³2026-08-08: 5.4 µg/m³2026-08-09: 4.1 µg/m³2026-08-10: 4.5 µg/m³2026-08-11: 11.3 µg/m³2026-08-12: 15.9 µg/m³2026-08-13: 24.0 µg/m³2026-08-14: 7.0 µg/m³2026-08-15: 6.7 µg/m³2026-08-16: 9.0 µg/m³2026-08-17: 4.9 µg/m³2026-08-18: 4.4 µg/m³2026-08-19: 4.1 µg/m³2026-08-20: 2.8 µg/m³2026-08-21: 3.3 µg/m³2026-08-22: 5.2 µg/m³2026-08-23: 5.5 µg/m³2026-08-24: 4.9 µg/m³2026-08-25: 4.6 µg/m³2026-08-26: 3.3 µg/m³2026-08-27: 4.5 µg/m³2026-08-28: 4.1 µg/m³2026-08-29: 4.6 µg/m³2026-08-30: 14.2 µg/m³2026-08-31: 14.5 µg/m³2026-09-01: 3.9 µg/m³2026-09-02: 3.7 µg/m³2026-09-03: 2.6 µg/m³2026-09-04: 2.1 µg/m³2026-09-05: 2.8 µg/m³2026-09-06: 3.7 µg/m³2026-09-07: 5.2 µg/m³2026-09-08: 8.9 µg/m³2026-09-09: 7.2 µg/m³2026-09-10: 6.0 µg/m³2026-09-11: 7.2 µg/m³2026-09-12: 16.9 µg/m³2026-09-13: 8.5 µg/m³2026-09-14: 6.9 µg/m³2026-09-15: 14.7 µg/m³2026-09-16: 12.8 µg/m³2026-09-17: 8.2 µg/m³2026-09-18: 2.9 µg/m³2026-09-19: 5.3 µg/m³2026-09-20: 7.8 µg/m³2026-09-21: 11.8 µg/m³2026-09-22: 10.3 µg/m³2026-09-23: 12.3 µg/m³2026-09-24: 21.4 µg/m³2026-09-25: 22.7 µg/m³2026-09-26: 16.8 µg/m³2026-09-27: 15.3 µg/m³2026-09-28: 8.1 µg/m³2026-09-29: 7.6 µg/m³2026-09-30: 9.5 µg/m³2026-10-01: no data
Good 0–9.0Moderate 9.1+Unhealthy for sensitive groups 35.5+Unhealthy 55.5+Very unhealthy 125.5+Hazardous 225.5+No data

32 of 339 measured days were over the WHO 24-hour guideline.

Daily world rank

#1#2287NovDecJanFebMarAprMayJunJulAugSep

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

2026 against 2025, month by month

15Jan 2025: 9.8 µg/m³Jan 2026: 7.8 µg/m³JanFeb 2025: 8.0 µg/m³Feb 2026: 10.0 µg/m³FebMar 2025: 10.6 µg/m³Mar 2026: 10.4 µg/m³MarApr 2025: 10.2 µg/m³Apr 2026: 7.7 µg/m³AprMay 2025: 9.2 µg/m³May 2026: 8.8 µg/m³MayJun 2025: 9.9 µg/m³Jun 2026: 6.5 µg/m³JunJul 2025: 13.3 µg/m³Jul 2026: 12.8 µg/m³JulAug 2025: 11.7 µg/m³Aug 2026: 8.0 µg/m³AugSep 2025: 6.8 µg/m³Sep 2026: 9.1 µg/m³SepOct 2025: 9.1 µg/m³OctNov 2025: 9.5 µg/m³NovDec 2025: 7.5 µg/m³Dec

Faded bars: 2025. A month shows once it has 10 measured days.

This week against past years

This weekThis week: 13.3 µg/m³13.320252025: 8.5 µg/m³8.520242024: 9.1 µg/m³9.120232023: 9.8 µg/m³9.8

Mean PM2.5 for 25 Sept to 1 Oct in each year. Dashed line: WHO 24-hour guideline.

Monitors

StationOperatorType
小林市小林市堤字金鳥居３０２０の１３政府標準利用規約（第2.0版） (Government Standard Terms of Use v2.0)Ministry of the Environment Air Pollutant Wide Area Monitoring SystemReference

The city's value is the median of its reference monitors each hour; low-cost sensors are listed but not counted when reference monitors exist. Data via OpenAQ; licences as listed. How we rank. Embed this on your site.

Other cities in Japan

Honmachi 9.6Onomichi 9.5Hita 9.4Ōzu 9.3Kanoya 9.3Kamisu 9.1Ōyanomachi-noboritate 9.0Minamata 9.0Hitoyoshi 8.9Owariasahi 8.9Hyūga 8.9Uekimachi-mōno 8.8

30-day averages, µg/m³. All of Japan →

Updated 2026-10-01 14:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.