Air quality in Iron County, UT

Includes Cedar City · EPA monitor readings, 2021 to 2025 · 57,000 people

A few bad days a year
Bad-air days a year
1
day with an AQI over 100

6 bad-air days in 5 years of readings, 2021 to 2025. Iron County is tied with 1 other Utah county for the 3rd fewest bad-air days of the 14 with monitors.

<1day unhealthy for everyoneAQI over 150, a year
42AQI on a typical dayGood: fine for everyone
6bad-air days since 2016Too few to show a season
176worst day since 2016Aug 7, 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 42 (Good)Worst day 176 (Unhealthy)
Good0 to 50Moderate51 to 100Sensitive groups101 to 150Unhealthy151 to 200Very unhealthy201 to 300Hazardous301 to 500

Bad-air days by month in Iron County

Bad air is rare here: 6 bad-air days in 8 years of daily readings since 2016, too few to show a season. Each tile is the average for that month.

Jan0
Feb0
Mar0
Apr0
May0
Jun0.2
Jul0
Aug0.4
Sep0
Oct0
Nov0
Dec0

The worst day since 2016 was August 7, 2021: AQI 176, from fine particles.

What causes it

The 6 bad-air days since 2016 were 3 fine-particle days (in August 2021), 2 ozone days (in June 2021 and June 2025) and 1 day set by another pollutant (on March 6, 2023).

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.

JFMApril: 0.0 ozone days a yearAMay: 0.6 ozone days a yearMJune: 0.2 smoky days a yearJune: 1.3 ozone days a yearJJuly: 0.0 smoky days a yearJuly: 0.7 ozone days a yearJAugust: 0.1 smoky days a yearAugust: 0.1 ozone days a yearASONDbad daysby month
See the numbers by month
CDC estimated bad-air days a year in each month in Iron County, 2001 to 2022
MonthFine particlesOzone
January00
February00
March00
April00
May00.6
June0.21.3
July00.7
August0.10.1
September00
October00
November00
December00

What helps in Iron County

The air here is clean most days: 6 bad-air days in 8 years of daily readings. Wildfire smoke can still drift in from far away, so it's worth being ready.

Check tomorrow's forecast

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

AirNow →

Keep a cheap backup

A box fan with a MERV 13 filter clamped to it cleans a room in a pinch.

Build one →

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.

Smoky days are rare here, so a purifier is optional. If you want one for wildfire season anyway, see the 3 models we'd buy, each with a verified smoke rating.

Every year since 2018

Bad-air days each year. The striped part is days unhealthy for everyone, over AQI 150. The worst recent year was 2021, with 4 bad-air days.

0123452018202042025101234520182020420251
Unhealthy for sensitive groups (101 to 150)Unhealthy or worse (over 150)
See the numbers by year
Bad-air days each year in Iron County
YearBad-air daysOver 150
201800
201900
202000
202141
202200
202310
202400
202510

Iron County and its neighbors

Bad-air days a year, 2021 to 2025. Utah counties with monitors averaged about 16 bad-air days a year, weighted by population.

Iron County1
Washington County1

Nearest counties with a full report: Clark County, NV (30 bad-air days a year), Mohave County, AZ (under 1 bad-air day a year).

Questions people ask about air in Iron County

How often is the air bad in Iron County?

From 2021 to 2025, monitors in Iron County recorded about 1 bad-air day a year with an AQI above 100, which is unhealthy for sensitive groups or worse. The worst year in that stretch was 2021, with 4 bad-air days.

What causes bad air in Iron County?

The 6 bad-air days since 2016 were 3 fine-particle days (in August 2021), 2 ozone days (in June 2021 and June 2025) and 1 day set by another pollutant (on March 6, 2023).

Where can I see today's air quality in Iron 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 Iron County is about 42, which is good, fine for everyone. Bad days are rare here, so check it when wildfire smoke is in the news.

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 365 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 Iron County almost no high-particle days 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.