Air quality in Muskegon County, MI

Includes Muskegon and Norton Shores · EPA monitor readings, 2021 to 2025 (ozone only) · 176,000 people

Some bad daysOnly ozone is measured
Bad-air days a year
6
days with an AQI over 100

About 1 day in 57. That's down from about 18 a year in the early 2000s. Muskegon County has the 4th most bad-air days of the 25 Michigan counties with monitors.

<1day unhealthy for everyoneAQI over 150, a year
39AQI on a typical dayGood: fine for everyone
May to Julworst monthsOzone, the only pollutant measured
187worst day since 2016Jun 21, 2022, ozone
How to read the AQIThe EPA's air score runs from 0 to 500. Higher is worse. Over 100 counts as a bad-air day.
Typical day 39 (Good)Worst day 187 (Unhealthy)
Good0 to 50Moderate51 to 100Sensitive groups101 to 150Unhealthy151 to 200Very unhealthy201 to 300Hazardous301 to 500

When bad air happens in Muskegon County

Average bad-air days in each month, from 9 years of daily readings since 2016. Most fall in May, June and July. Only ozone is measured here.

Jan0
Feb0
Mar0
Apr0
May0.6
Jun3.2
Jul1.3
Aug0.3
Sep0.1
Oct0
Nov0
Dec0
01234JanFebMarAprMayJunJulAugSepOctNovDecOZONE SEASON01234JFMAMJJASONDOZONE
Fine particles (smoke, soot)Ozone (smog)Bars stack in that order, from the bottom.
See the numbers by month
Average bad-air days a year in each month in Muskegon County, from 9 years of daily readings
MonthOzoneFine particlesAll
January000
February000
March000
April000
May0.600.6
June3.203.2
July1.301.3
August0.300.3
September0.100.1
October000
November000
December000

The worst day since 2016 was June 21, 2022: AQI 187, from ozone.

What causes it

Ozone is the only pollutant measured here. Every bad day counted here was an ozone day: smog that builds on hot, sunny afternoons. Monitors here don't measure fine particles, so smoky days aren't in these counts.

CDC's model estimates about 0.0 days a year with high fine particles at the county's worst spot, 2018 to 2022. See the estimates on the map

CDC estimates by month, 2001 to 2022

The CDC's model counts bad-air days at the county's worst spot, from monitors and satellites. Particles (brown) fill the inside of the ring and ozone (blue) the outside.

January: 0.0 smoky days a yearJFebruary: 0.2 smoky days a yearFMarch: 0.2 smoky days a yearMApril: 0.5 ozone days a yearAMay: 1.8 ozone days a yearMJune: 0.4 smoky days a yearJune: 4.7 ozone days a yearJJuly: 0.2 smoky days a yearJuly: 4.6 ozone days a yearJAugust: 0.4 smoky days a yearAugust: 2.9 ozone days a yearASeptember: 0.2 smoky days a yearSeptember: 1.1 ozone days a yearSONovember: 0.1 smoky days a yearNDecember: 0.1 smoky days a yearDbad daysby month
See the numbers by month
CDC estimated bad-air days a year in each month in Muskegon County, 2001 to 2022
MonthFine particlesOzone
January00
February0.20
March0.20
April00.5
May01.8
June0.44.7
July0.24.6
August0.42.9
September0.21.1
October00
November0.10
December0.10

What helps in Muskegon County

Monitors here track ozone, which builds on hot afternoons, so timing helps. They don't track smoke, so it's worth having a clean room ready too.

Move workouts to the morning

Ozone peaks on hot, sunny afternoons. Mornings are usually cleaner.

Ozone guide →

Check tomorrow's forecast

AirNow posts an air quality forecast by ZIP code, usually the day before.

AirNow →

Keep one room clean on smoky days

Shut the windows and run an air purifier sized for the room.

Choosing a purifier →

For today's reading and tomorrow's forecast, check AirNow by ZIP code. Its fire and smoke map adds smoke plumes.

Purifiers catch smoke but don't remove ozone, and smoky days are rare here. If you want one for wildfire season anyway, see the 3 models we'd buy, each with a verified smoke rating.

Every year since 2000

Bad-air days each year. The striped part is days unhealthy for everyone, over AQI 150. The worst recent year was 2023, with 11 bad-air days.

0204020002005201035202020252020402000201035202020252
Unhealthy for sensitive groups (101 to 150)Unhealthy or worse (over 150)
See the numbers by year
Bad-air days each year in Muskegon County
YearBad-air daysOver 150
2000162
2001269
2002277
2003195
200440
20053010
2006135
2007224
200851
200951
201080
201183
2012359
201360
201750
201863
201910
202060
202180
202272
2023110
202440
202520

Muskegon County and its neighbors

Bad-air days a year, 2021 to 2025. Michigan counties with monitors averaged about 7 bad-air days a year, weighted by population.

Questions people ask about air in Muskegon County

How often is the air bad in Muskegon County?

From 2021 to 2025, monitors in Muskegon County recorded about 6 bad-air days a year with an AQI above 100, which is unhealthy for sensitive groups or worse. The worst year in that stretch was 2023, with 11 bad-air days.

What causes bad air in Muskegon County?

Every bad day counted here was an ozone day: smog that builds on hot, sunny afternoons. Bad days cluster in May, June and July. Monitors here don't measure fine particles, so smoky days aren't in these counts.

Where can I see today's air quality in Muskegon County?

AirNow, run by the EPA and its partners, shows the current AQI and tomorrow's forecast for your ZIP code. Its fire and smoke map adds smoke plumes. On a typical day the AQI in Muskegon County is about 39, which is good, fine for everyone. Check it most in May, June and July, when bad days here cluster.

About these numbers

Day counts come from the EPA's county air quality summaries, which take the worst reading across a county's monitors each day. Monitors here reported on about 247 days a year from 2021 to 2025; some run only in ozone season, so a few bad days can go uncounted. A county is large, and your street can be cleaner or worse. CDC's model, which estimates every county from monitors and satellites, gives the worst spot in Muskegon County almost no high-particle days and about 12 high-ozone days a year from 2018 to 2022.

Sources: EPA AirData county AQI summaries (2000 to 2025) and daily county AQI (2016 to 2025); CDC Environmental Public Health Tracking Network modeled PM2.5 and ozone (2001 to 2022). Updated November 8, 2026.