What is the air quality trend in Johnston?

Over the past 15 days, Johnston had an average AQI of 55 based on station measurements. The worst day was 2026-07-20 with AQI 79.

How is Johnston air quality measured?

Air quality in Johnston 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 Johnston, United States

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

Historical PM2.5 and AQI trend from monitoring stations near Johnston, United States.

Current AQI
Moderate Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

254h

PM2.5 Station

254h · 1 station

Temperature GFS model

56pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-07-22	55	55–55	14.0 µg/m³	1h	1
2026-07-21	54	21–82	14.4 µg/m³	15h	1
2026-07-20	79	15–154	25.7 µg/m³	14h	1
2026-07-19	67	16–172	23.8 µg/m³	15h	1
2026-07-18	39	1–93	10.6 µg/m³	17h	1
2026-07-17	53	30–91	14.5 µg/m³	20h	1
2026-07-16	47	29–97	12.4 µg/m³	16h	1
2026-07-15	54	19–99	15.2 µg/m³	20h	1
2026-07-14	51	20–79	14.0 µg/m³	18h	1
2026-07-13	59	25–87	16.9 µg/m³	17h	1
2026-07-12	53	16–91	14.5 µg/m³	22h	1
2026-07-11	49	25–92	13.0 µg/m³	21h	1
2026-07-10	46	23–87	11.8 µg/m³	20h	1
2026-07-09	64	33–112	18.7 µg/m³	20h	2
2026-07-08	58	28–92	16.7 µg/m³	18h	2

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