Why is the air quality bad in Somerset today?

Poor air quality in Somerset is usually driven by one dominant pollutant — most often fine particle pollution (PM2.5) from wildfire smoke, vehicle exhaust, or industry, or ground-level ozone (smog) that builds on hot, sunny, stagnant days. The AQI at the top of this page names which pollutant is highest right now; that pollutant is what's making the air "bad," and weather — heat, calm wind, or smoke blown in from elsewhere — is usually why it spikes on a given day.

Is it safe to exercise outside in Somerset right now?

It depends on the AQI. Below 100 (Good or Moderate) it's generally fine to run or work out outdoors. From 101–150 (Unhealthy for Sensitive Groups), people with asthma, heart conditions, kids, and older adults should shorten or move workouts indoors. At 151+ (Unhealthy) everyone should cut back on hard outdoor exertion, because exercise makes you breathe more polluted air deeper into your lungs. The live verdict at the top of this page gives the go/no-go for Somerset right now.

What's the main pollutant in Somerset's air?

The two pollutants that most often drive Somerset's AQI are fine particulate matter (PM2.5) and ground-level ozone. PM2.5 tends to dominate in winter, near traffic and industry, and during wildfire smoke events; ozone tends to dominate on hot, sunny summer afternoons. This page identifies the dominant pollutant live — it's the one whose sub-index matches the overall AQI — so you can see which is the problem today rather than guessing by season.

Somerset, Kentucky Air Quality

Somerset air quality today — the AQI, the main pollutant, and whether it’s safe to exercise outside right now

Somerset, KY · Air quality right now

The air quality index in Somerset, KY is 40 (Good) right now — safe for outdoor activity.

Is it safe to be outside in Somerset today?

Yes — air quality is Good (AQI 40)

Air is clean — great for outdoor activity.Main pollutant: PM2.5

Pollutants right now

PM2.58.5 µg/m³Main pollutantfine particles — smoke, exhaust, soot
PM108.5 µg/m³coarse particles — dust, pollen, ash
Ozone76 µg/m³smog — builds on hot, sunny days
NO₂0.7 µg/m³nitrogen dioxide — traffic, combustion

ExerciseOK to run — no air-quality limits on outdoor exercise.

Wildfire smoke & fire weather in Somerset

Smoke checkFine-particle (PM2.5) level right now: 8.5 µg/m³ Good on the EPA PM2.5 scale. PM2.5-based; smoke is one possible source — traffic, industry, and dust raise the same number.

Wildfire smoke shows up in air-quality data as fine-particle (PM2.5) pollution — it’s the number that climbs when smoke moves in. A Fire Weather Watch from the National Weather Service means critical fire-weather conditions — dry fuels, low humidity, gusty wind — are possible in the next day or two; a Red Flag Warning means they’re happening or imminent. On smoky days, EPA and AirNow guidance is to limit time outdoors, keep windows closed, run filtration if you have it, and wear an N95 if you must be outside. See where smoke and storms sit right now on the live weather map.

How to read Somerset’s air quality

Air quality is reported as the EPA Air Quality Index (AQI), a 0–500 scale set by whichever pollutant is worst at the moment — where an AQI under 100 is a safe day for outdoor activity in Somerset and above 100 people with asthma, heart conditions, the very young, and older adults should start to scale back.

For the full six-category scale — every band, its color, and the pollutants behind the number — see the AQI scale guide.

Air quality over time in Somerset

Across the EPA’s county records from 2020 to 2025, Somerset’s cleanest year was 2020 (median AQI 38) and its most polluted was 2021 (median AQI 45); the typical (median) day has held roughly steady since 2020.

Somerset’s county air-quality record by year — the median and days in each AQI category, from the EPA’s Annual AQI by County summaries.
Year	Median AQI	Good	Moderate	USG	Main pollutant
2020	38	246	37	0	Ozone
2021	45	229	131	1	PM2.5
2022	42	259	100	0	PM2.5
2023	45	232	129	2	PM2.5
2024	41	292	74	0	PM2.5
2025	40	297	68	0	PM2.5

“USG” is Unhealthy for Sensitive Groups (AQI 101–150); “Unhealthy+” combines the Unhealthy, Very Unhealthy, and Hazardous days. In 2024 the EPA tightened the annual fine-particle (PM2.5) standard to 9 µg/m³ from the previous 12 µg/m³, so counties near the old limit read worse against the new one. Source: EPA AQS annual summaries, 2020–2025.

Frequently asked

Why is the air quality bad in Somerset today?: Poor air quality in Somerset is usually driven by one dominant pollutant — most often fine particle pollution (PM2.5) from wildfire smoke, vehicle exhaust, or industry, or ground-level ozone (smog) that builds on hot, sunny, stagnant days. The AQI at the top of this page names which pollutant is highest right now; that pollutant is what's making the air "bad," and weather — heat, calm wind, or smoke blown in from elsewhere — is usually why it spikes on a given day.
Is it safe to exercise outside in Somerset right now?: It depends on the AQI. Below 100 (Good or Moderate) it's generally fine to run or work out outdoors. From 101–150 (Unhealthy for Sensitive Groups), people with asthma, heart conditions, kids, and older adults should shorten or move workouts indoors. At 151+ (Unhealthy) everyone should cut back on hard outdoor exertion, because exercise makes you breathe more polluted air deeper into your lungs. The live verdict at the top of this page gives the go/no-go for Somerset right now.
What's the main pollutant in Somerset's air?: The two pollutants that most often drive Somerset's AQI are fine particulate matter (PM2.5) and ground-level ozone. PM2.5 tends to dominate in winter, near traffic and industry, and during wildfire smoke events; ozone tends to dominate on hot, sunny summer afternoons. This page identifies the dominant pollutant live — it's the one whose sub-index matches the overall AQI — so you can see which is the problem today rather than guessing by season.

More for Somerset

See the full Somerset, KY weather forecast — hour-by-hour outlook, NOAA radar, satellite, and air quality.