Bad Air Days in Tuscola County, Michigan: 2 a Year

2 bad air days a year

Fewer bad air days than most monitored US counties. Ranked 562 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (0% particle days).

When the bad days come in Tuscola

Most bad days here fall in June and May and April. 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.

Better or worse than it was

In 2000 to 2009 this county averaged 10 bad days a year; in 2016 to 2025, 2. The air has improved. The worst recent year was 2023, with 6 bad days on 362 monitored days.

Date	AQI	Main pollutant
2023-06-29	154	Ozone
2023-06-30	133	Ozone
2016-06-19	115	Ozone
2023-06-02	115	Ozone
2016-05-24	112	Ozone

The air on a normal day

Across 3,558 monitored days from 2016 to 2025, the air in Tuscola County rated Good on 93% of them, more often than the 72% typical of monitored counties, and Moderate on 7%. The median day sat at AQI 34; one day in ten went above 48.

The pollutant setting the AQI on an ordinary day here:

ozone100%3,558 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	358	329	28	1	0	35	112
2024	364	331	33	0	0	34	84
2023	362	324	32	6	1	34	154
2022	361	334	26	1	0	34	105
2021	353	327	25	1	0	34	101
2020	343	330	11	2	0	32	101
2019	355	345	10	0	0	33	77
2018	356	324	31	1	0	35	105
2017	346	326	20	0	0	33	87
2016	360	332	24	4	0	34	115
2015	340	321	19	0	0	34	100
2014	360	339	21	0	0	34	87
2013	359	328	30	1	0	34	112
2012	348	288	45	15	1	34	159
2011	349	321	23	5	0	36	136
2010	361	326	35	0	0	36	100

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

Elsewhere in Michigan

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, and on why a purifier does not touch ozone in smoke vs ozone.