What is the air quality trend in Nagano?

Over the past 15 days, Nagano had an average AQI of 40 based on station measurements. The worst day was 2026-10-16 with AQI 52.

How is Nagano air quality measured?

Air quality in Nagano is measured by ground-level monitoring stations that report PM2.5 and PM10 concentrations hourly. CERNS.IO aggregates readings from nearby stations and converts PM2.5 to the US EPA Air Quality Index (AQI) scale.

Air Quality History for Nagano, Japan

Name: Nagano Air Quality History
Creator: CERNS.IO
License: https://creativecommons.org/licenses/by/4.0/

Historical PM2.5 and AQI trend from monitoring stations near Nagano, Japan.

114

Current AQI
Unhealthy for sensitive groups Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

330h

PM2.5 Station

330h · 6 stations

Temperature GFS model

56pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-10-21	33	25–40	7.9 µg/m³	7h	6
2026-10-20	37	18–89	9.2 µg/m³	24h	5
2026-10-19	38	16–79	9.5 µg/m³	24h	5
2026-10-18	32	15–53	7.7 µg/m³	24h	6
2026-10-17	36	18–52	8.6 µg/m³	24h	5
2026-10-16	52	18–116	13.9 µg/m³	24h	4
2026-10-15	36	14–69	9.0 µg/m³	24h	4
2026-10-14	46	17–95	12.8 µg/m³	24h	5
2026-10-13	45	17–79	11.5 µg/m³	23h	4
2026-10-12	39	2–99	10.2 µg/m³	22h	4
2026-10-11	47	15–180	14.5 µg/m³	24h	4
2026-10-10	40	18–98	10.2 µg/m³	24h	4
2026-10-09	42	9–125	11.0 µg/m³	24h	4
2026-10-08	42	24–69	10.3 µg/m³	24h	5
2026-10-07	39	23–56	9.4 µg/m³	14h	5

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