Air quality in Stearns County, MN

Includes St. Cloud · EPA monitor readings, 2021 to 2025 · 158,000 people

Some bad daysMostly summer smoke
Bad-air days a year
6
days with an AQI over 100

About 1 day in 59. That's up from about 2 a year in the early 2000s. Stearns County is tied with 1 other Minnesota county for the 7th most bad-air days of the 20 with monitors.

2days unhealthy for everyoneAQI over 150, a year
41AQI on a typical dayGood: fine for everyone
May to Julworst monthsSmoke and particles in summer and fall
252worst day since 2016Jul 29, 2021, fine particles
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 41 (Good)Worst day 252 (Very unhealthy)
Good0 to 50Moderate51 to 100Sensitive groups101 to 150Unhealthy151 to 200Very unhealthy201 to 300Hazardous301 to 500

When bad air happens in Stearns County

Average bad-air days in each month, from 10 years of daily readings since 2016. Most fall in May, June and July.

Jan0.1
Feb0
Mar0
Apr0
May0.7
Jun0.6
Jul1.3
Aug0.5
Sep0
Oct0
Nov0
Dec0
012JanFebMarAprMayJunJulAugSepOctNovDecSMOKE SEASON012JFMAMJJASONDSMOKE
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 Stearns County, from 10 years of daily readings
MonthOzoneFine particlesAll
January00.10.1
February000
March000
April000
May0.60.10.7
June0.30.30.6
July01.31.3
August00.50.5
September000
October000
November000
December000

The worst day since 2016 was July 29, 2021: AQI 252, from fine particles.

What causes it

The pollutant that pushed the AQI over 100 on each of the 32 bad-air days since 2016.

72%particles
28%Ozone: smog that forms in sunlight on hot days
72%Fine particles: smoke and soot

Most bad days here are fine-particle days in summer and fall, the months when wildfire smoke drives particle pollution.

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: 0.1 smoky days a yearFMarch: 0.0 smoky days a yearMApril: 0.0 ozone days a yearAMay: 0.0 ozone days a yearMJune: 0.3 ozone days a yearJJuly: 0.3 smoky days a yearJuly: 0.0 ozone days a yearJAugust: 0.1 smoky days a yearASONDecember: 0.1 smoky days a yearDbad daysby month
See the numbers by month
CDC estimated bad-air days a year in each month in Stearns County, 2001 to 2022
MonthFine particlesOzone
January00
February0.10
March00
April00
May00
June00.3
July0.30
August0.10
September00
October00
November00
December0.10

What helps in Stearns County

Most bad days here are smoke and other fine particles. Filtering the air at home helps most.

Keep one room clean on smoky days

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

Choosing a purifier →

Upgrade the furnace filter

Use MERV 13 if your system can take it, and run the fan on smoky days.

Furnace filters →

Wear an N95 outside on smoky days

A well-fitted N95 helps. Cloth and surgical masks do little against smoke.

Wildfire smoke guide →

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

Purifiers with a verified smoke rating

For a clean room on smoky days. Each has a smoke CADR tested by AHAM's independent program and is certified by California as a mechanical cleaner, so it makes no ozone.

Bedroom or small room

Levoit Vital 100S-P

143 smoke CADR

Everyday
up to 222 sq ft
Heavy smoke
up to 143 sq ft
Filters
about $40 a year

The cheapest unit we found with a verified smoke rating. Enough for a bedroom clean room.

$119.99 at Levoit
Best value for smoke

Levoit Vital 200S-P

250 smoke CADR

Everyday
up to 388 sq ft
Heavy smoke
up to 250 sq ft
Filters
about $50 a year

The most verified smoke cleaning per dollar of any qualifying model: 75% more than the 100S-P for $50 more.

$169.99 at Levoit
Living room or open floor

Levoit Core 600S-P

391 smoke CADR

Everyday
up to 606 sq ft
Heavy smoke
up to 391 sq ft
Filters
$60 to $120 a year

For a big room or a small apartment. Buy the LAP-C601S-WUS version, which CARB lists as mechanical.

$299.99 at Levoit

Why all 3 are Levoit: of the models we checked that pass both tests, these give the most verified smoke cleaning per dollar at each room size. Medify's MA-25 and MA-40 also pass but cost more for the same cleaning.

Ratings from the AHAM Verifide directory and CARB's certified list. Prices from Levoit's site, checked November 7, 2026; they change. We don't earn anything from these links. How to pick a purifier

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 14 bad-air days.

0510152020002005201020152020142025110510152020002010202014202511
Unhealthy for sensitive groups (101 to 150)Unhealthy or worse (over 150)
See the numbers by year
Bad-air days each year in Stearns County
YearBad-air daysOver 150
200030
200100
200210
200320
200440
200531
200600
200760
200831
200920
201020
201120
201210
201300
201400
201511
201600
201700
201810
201900
202000
202163
202200
2023143
202400
2025113

Stearns County and its neighbors

Bad-air days a year, 2021 to 2025. Minnesota counties with monitors averaged about 6 bad-air days a year, weighted by population.

Wright County8
Stearns County6

Nearest counties with a full report: Hennepin County, MN (7 bad-air days a year), Anoka County, MN (7 bad-air days a year).

Questions people ask about air in Stearns County

How often is the air bad in Stearns County?

From 2021 to 2025, monitors in Stearns 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 14 bad-air days.

What causes bad air in Stearns County?

Most bad days here are fine-particle days in summer and fall, the months when wildfire smoke drives particle pollution. Bad days cluster in May, June and July.

Where can I see today's air quality in Stearns 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 Stearns County is about 41, 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 345 days a year from 2021 to 2025. 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 Stearns County about 1 high-particle day and almost no 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.