Marion, Indiana Air Quality

Marion County, Indiana (IN)

→ Stableover 10 years

Air Quality Grade

51/100

Current Median AQI

Moderate

5-Year Avg AQI

10-Year Change

Worse

Unhealthy Days/yr

5-year average

PM2.5

Primary Pollutant

Fine Particulate Matter (PM2.5)

10-Year AQI Trend

The solid line shows the median AQI each year. The dashed line shows the 90th percentile (worst 10% of days).

Air Quality Day Breakdown

Number of days per year in each EPA AQI category. Green = Good (AQI 0-50), Yellow = Moderate (51-100), Orange = Unhealthy for Sensitive Groups (101-150), Red = Unhealthy or worse (151+).

Year-by-Year Data

Year	Median AQI	90th Pct	Max AQI	Good Days	Moderate	Unhealthy+	Pollutant
2023	60	89	259	84	260	21	PM2.5
2022	56	80	154	101	251	13	PM2.5
2021	58	81	114	81	278	6	PM2.5
2020	55	72	144	110	250	6	PM2.5
2019	58	74	112	78	283	4	PM2.5
2018	55	73	158	105	249	11	PM2.5
2017	54	71	122	134	227	4	PM2.5
2016	55	77	143	111	244	11	PM2.5
2015	56	74	159	129	233	3	PM2.5
2014	58	79	209	85	273	7	PM2.5

What This Means for Marion County Residents

Marion, Indiana has received an Air Quality Grade of C (51/100) based on a decade of EPA monitoring data. The current median AQI of 60 falls in the "Moderate" range.

The primary pollutant affecting this area is Fine Particulate Matter (PM2.5). Over the past 5 years, this area has averaged 10 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity.