Air quality in Cecil County, MD

Includes Elkton · EPA monitor readings, 2021 to 2025 · 104,000 people

A few bad days a yearMostly ozone
Bad-air days a year
3
days with an AQI over 100

16 bad-air days in 5 years of readings, 2021 to 2025. That's down from about 29 a year in the early 2000s. Cecil County has the 5th most bad-air days of the 16 Maryland counties with monitors.

<1day unhealthy for everyoneAQI over 150, a year
43AQI on a typical dayGood: fine for everyone
May to Julworst monthsOzone on hot afternoons
190worst day since 2016Jun 7, 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 43 (Good)Worst day 190 (Unhealthy)
Good0 to 50Moderate51 to 100Sensitive groups101 to 150Unhealthy151 to 200Very unhealthy201 to 300Hazardous301 to 500

When bad air happens in Cecil County

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

Jan0
Feb0
Mar0
Apr0.2
May0.7
Jun1.9
Jul0.8
Aug0.2
Sep0.6
Oct0
Nov0
Dec0
012JanFebMarAprMayJunJulAugSepOctNovDecOZONE SEASON012JFMAMJJASONDOZONE
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 Cecil County, from 10 years of daily readings
MonthOzoneFine particlesAll
January000
February000
March000
April0.200.2
May0.700.7
June1.40.51.9
July0.70.10.8
August0.200.2
September0.600.6
October000
November000
December000

The worst day since 2016 was June 7, 2023: AQI 190, from fine particles.

What causes it

The pollutant that pushed the AQI over 100 on each of the 44 bad-air days since 2016.

86%ozone
86%Ozone: smog that forms in sunlight on hot days
14%Fine particles: smoke and soot

Most bad days here are ozone days: smog that builds on hot, sunny afternoons.

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: 0.3 smoky days a yearJFebruary: 0.1 smoky days a yearFMApril: 0.7 ozone days a yearAMay: 0.1 smoky days a yearMay: 2.0 ozone days a yearMJune: 0.6 smoky days a yearJune: 5.1 ozone days a yearJJuly: 0.8 smoky days a yearJuly: 5.2 ozone days a yearJAugust: 0.8 smoky days a yearAugust: 4.0 ozone days a yearASeptember: 1.4 ozone days a yearSOctober: 0.0 smoky days a yearOctober: 0.1 ozone days a yearONovember: 0.1 smoky days a yearNDecember: 0.2 smoky days a yearDbad daysby month
See the numbers by month
CDC estimated bad-air days a year in each month in Cecil County, 2001 to 2022
MonthFine particlesOzone
January0.30
February0.10
March00
April00.7
May0.12.0
June0.65.1
July0.85.2
August0.84.0
September01.4
October00.1
November0.10
December0.20

What helps in Cecil County

Most bad days here are ozone, which builds on hot afternoons. Timing helps most; filters don't remove ozone.

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 6 bad-air days.

020406020004220052010201520202025202040602000422010202020252
Unhealthy for sensitive groups (101 to 150)Unhealthy or worse (over 150)
See the numbers by year
Bad-air days each year in Cecil County
YearBad-air daysOver 150
20002718
20013916
20024217
2003185
2004202
2005299
2006285
2007335
2008244
200980
2010222
2011126
2012245
201350
201450
201551
2016101
201781
201870
201930
202000
202140
202210
202364
202430
202520

Cecil County and its neighbors

Bad-air days a year, 2021 to 2025. Maryland counties with monitors averaged about 3 bad-air days a year, weighted by population.

Questions people ask about air in Cecil County

How often is the air bad in Cecil County?

From 2021 to 2025, monitors in Cecil County recorded about 3 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 6 bad-air days.

What causes bad air in Cecil County?

Most bad days here are ozone days: smog that builds on hot, sunny afternoons. Bad days cluster in May, June and July.

Where can I see today's air quality in Cecil 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 Cecil County is about 43, 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 360 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 Cecil County almost no high-particle days and about 2 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.