Why is the air quality bad in Dolores today?

Poor air quality in Dolores 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 Dolores 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 Dolores right now.

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

The two pollutants that most often drive Dolores'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.

Dolores, Colorado Air Quality

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

Dolores, CO · Air quality right now

The air quality index in Dolores, CO is 35 (Good) right now — safe for outdoor activity.

Is it safe to be outside in Dolores today?

Yes — air quality is Good (AQI 35)

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

Pollutants right now

PM2.54.0 µg/m³fine particles — smoke, exhaust, soot
PM105.2 µg/m³coarse particles — dust, pollen, ash
Ozone107 µg/m³Main pollutantsmog — builds on hot, sunny days
NO₂0.6 µg/m³nitrogen dioxide — traffic, combustion

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

Wildfire smoke & fire weather in Dolores

Smoke checkFine-particle (PM2.5) level right now: 4.0 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 Dolores’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 Dolores 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 Dolores

Across the EPA’s county records from 2020 to 2025, Dolores’s cleanest year was 2020 (median AQI 44) and its most polluted was 2024 (median AQI 45); the typical (median) day has held roughly steady since 2020.

Dolores’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	44	301	63	2	Ozone
2021	44	280	83	2	Ozone
2022	44	300	65	0	Ozone
2023	44	291	74	0	Ozone
2024	45	262	103	1	Ozone
2025	45	274	90	1	Ozone

“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 Dolores today?: Poor air quality in Dolores 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 Dolores 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 Dolores right now.
What's the main pollutant in Dolores's air?: The two pollutants that most often drive Dolores'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 Dolores

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