Bad Air Days in Stearns County, Minnesota: 3 a Year

3 bad air days a year

About the middle of monitored US counties. Ranked 340 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (72% particle days).

Which months to watch

Most bad days here fall in July and May and June and August. Averaged over 2016 to 2025.

What actually helps here

Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
On the odd bad day, check AirNow and keep windows shut.

The record for Stearns

In 2000 to 2009 this county averaged 2 bad days a year; in 2016 to 2025, 3. Not much has changed. The worst recent year was 2023, with 14 bad days on 365 monitored days.

Date	AQI	Main pollutant
2021-07-29	252	PM2.5
2023-06-14	184	PM2.5
2021-07-30	182	PM2.5
2025-07-12	165	PM2.5
2025-08-01	157	PM2.5

An ordinary day in Stearns

Across 3,533 monitored days from 2016 to 2025, the air in Stearns County rated Good on 77% of them, more often than the 72% typical of monitored counties, and Moderate on 22%. The median day sat at AQI 38; one day in ten went above 61.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)57%2,004 days
ozone43%1,529 days

Stearns County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	357	270	76	11	3	37	165
2024	366	282	84	0	0	39	97
2023	365	199	152	14	3	48	184
2022	277	204	73	0	0	39	78
2021	362	261	95	6	3	40	252
2020	366	309	57	0	0	36	80
2019	344	290	54	0	0	34	94
2018	365	283	81	1	0	38	101
2017	365	294	71	0	0	37	87
2016	366	318	48	0	0	33	97
2015	355	306	48	1	1	37	151
2014	358	285	73	0	0	37	89
2013	359	273	86	0	0	39	85
2012	366	239	126	1	0	43	105
2011	355	225	128	2	0	42	101
2010	359	244	113	2	0	40	120

*2025 may be a partial year in EPA's file.

Nearby counties on file

How this is counted

A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day.