Air quality in Jefferson County, AL

Includes Birmingham · EPA monitor readings, 2021 to 2025 · 675,000 people

Some bad daysOzone and fine particles
Bad-air days a year
7
days with an AQI over 100

About 1 day in 52. That's down from about 70 a year in the early 2000s. Jefferson County has the most bad-air days of the 14 Alabama counties with monitors.

1day unhealthy for everyoneAQI over 150, a year
56AQI on a typical dayModerate: fine for most people
Jun to Augworst monthsOzone and fine particles
255worst day since 2016Jul 30, 2023, 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 56 (Moderate)Worst day 255 (Very unhealthy)
Good0 to 50Moderate51 to 100Sensitive groups101 to 150Unhealthy151 to 200Very unhealthy201 to 300Hazardous301 to 500

When bad air happens in Jefferson County

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

Jan0.1
Feb0
Mar0.5
Apr0.2
May0.6
Jun1.8
Jul1.0
Aug0.9
Sep0.6
Oct0.5
Nov0.1
Dec0.3
012JanFebMarAprMayJunJulAugSepOctNovDecOZONE SEASONPARTICLES012JFMAMJJASONDOZONEPARTICLES
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 Jefferson County, from 10 years of daily readings
MonthOzoneFine particlesAll
January00.10.1
February000
March0.10.40.5
April0.200.2
May0.600.6
June1.30.51.8
July0.50.51.0
August0.40.50.9
September0.50.10.6
October0.40.10.5
November00.10.1
December00.30.3

The worst day since 2016 was July 30, 2023: AQI 255, from fine particles.

What causes it

The pollutant that pushed the AQI over 100 on each of the 67 bad-air days since 2016.

60%ozone
60%Ozone: smog that forms in sunlight on hot days
39%Fine particles: smoke and soot
1%Other gases, such as nitrogen dioxide

Bad days here come from both ozone on hot afternoons and fine particles such as smoke.

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 yearJFMarch: 0.1 smoky days a yearMApril: 0.1 smoky days a yearApril: 0.9 ozone days a yearAMay: 0.7 smoky days a yearMay: 1.7 ozone days a yearMJune: 0.6 smoky days a yearJune: 3.5 ozone days a yearJJuly: 1.1 smoky days a yearJuly: 2.6 ozone days a yearJAugust: 1.4 smoky days a yearAugust: 2.9 ozone days a yearASeptember: 0.5 smoky days a yearSeptember: 1.3 ozone days a yearSOctober: 0.1 smoky days a yearOctober: 0.3 ozone days a yearONovember: 0.2 smoky days a yearNDbad daysby month
See the numbers by month
CDC estimated bad-air days a year in each month in Jefferson County, 2001 to 2022
MonthFine particlesOzone
January00
February00
March0.10
April0.10.9
May0.71.7
June0.63.5
July1.12.6
August1.42.9
September0.51.3
October0.10.3
November0.20
December00

What helps in Jefferson County

Bad days here come from ozone and fine particles, so it takes timing and filtering.

Move workouts to the morning

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

Ozone guide →

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 →

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 20 bad-air days.

020406080100120200010220052010201520202025202040608010012020001022010202020252
Unhealthy for sensitive groups (101 to 150)Unhealthy or worse (over 150)
See the numbers by year
Bad-air days each year in Jefferson County
YearBad-air daysOver 150
200010229
200110130
20026011
2003452
2004404
2005609
20066913
20077317
2008294
200960
2010304
2011386
2012204
201320
201460
201550
201691
201730
201841
2019130
202030
202152
202220
2023205
202460
202520

Jefferson County and its neighbors

Bad-air days a year, 2021 to 2025. Alabama counties with monitors averaged about 2 bad-air days a year, weighted by population.

Jefferson County7
Shelby County<1
Tuscaloosa County<1

Nearest county with a full report: Etowah County, AL (under 1 bad-air days a year).

Questions people ask about air in Jefferson County

How often is the air bad in Jefferson County?

From 2021 to 2025, monitors in Jefferson County recorded about 7 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 20 bad-air days.

What causes bad air in Jefferson County?

Bad days here come from both ozone on hot afternoons and fine particles such as smoke. Bad days cluster in June, July and August.

Where can I see today's air quality in Jefferson 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 Jefferson County is about 56, which is moderate, fine for most people. Check it most in June, July and August, 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 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 Jefferson County almost no high-particle days and about 1 high-ozone day 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.