EnviroNearby

Uintah County, Utah air quality history

Daily Air Quality Index summaries from EPA monitors in Uintah, Utah, 1980–2025.

58%
Good days in 2025
48
Median daily AQI, 2025
4
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Uintah, Utah on 365 days. 213 of those days (58%) were in the Good range, and the median daily AQI was 48. That median is higher than the typical monitored county in Utah (median 45 across 15 counties), and higher than the typical monitored U.S. county (40). The main pollutant was ozone on 351 days. Across the years with fuller monitoring, the share of Good days fell: an average of 84% in 1980–2007 versus 53% in 2023–2025.

Years with fewer than 120 monitored days (2001, 2002, 2003, 2004, 2005, 2006…) are shown in the table but left out of comparisons and trend statements.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%1980: Good 223 of 224 days1980: Moderate 1 of 224 days19801983: Good 166 of 178 days1983: Moderate 12 of 178 days2000: Good 16 of 16 days20002001: Good 51 of 51 days2002: Good 59 of 59 days20022003: Good 55 of 55 days2004: Good 50 of 50 days20042005: Good 45 of 45 days2006: Good 49 of 49 days20062007: Good 96 of 163 days2007: Moderate 67 of 163 days2008: Good 76 of 166 days2008: Moderate 90 of 166 days20082009: Good 172 of 254 days2009: Moderate 80 of 254 days2009: Unhealthy for Sensitive Groups 1 of 254 days2009: Unhealthy 1 of 254 days2010: Good 156 of 365 days2010: Moderate 162 of 365 days2010: Unhealthy for Sensitive Groups 16 of 365 days2010: Unhealthy 18 of 365 days2010: Very Unhealthy 13 of 365 days20102011: Good 179 of 365 days2011: Moderate 154 of 365 days2011: Unhealthy for Sensitive Groups 13 of 365 days2011: Unhealthy 14 of 365 days2011: Very Unhealthy 5 of 365 days2012: Good 157 of 366 days2012: Moderate 193 of 366 days2012: Unhealthy for Sensitive Groups 15 of 366 days2012: Unhealthy 1 of 366 days20122013: Good 126 of 365 days2013: Moderate 175 of 365 days2013: Unhealthy for Sensitive Groups 22 of 365 days2013: Unhealthy 23 of 365 days2013: Very Unhealthy 19 of 365 days2014: Good 229 of 365 days2014: Moderate 128 of 365 days2014: Unhealthy for Sensitive Groups 6 of 365 days2014: Unhealthy 2 of 365 days20142015: Good 242 of 365 days2015: Moderate 121 of 365 days2015: Unhealthy for Sensitive Groups 2 of 365 days2016: Good 234 of 366 days2016: Moderate 121 of 366 days2016: Unhealthy for Sensitive Groups 4 of 366 days2016: Unhealthy 5 of 366 days2016: Very Unhealthy 2 of 366 days20162017: Good 200 of 365 days2017: Moderate 154 of 365 days2017: Unhealthy for Sensitive Groups 3 of 365 days2017: Unhealthy 6 of 365 days2017: Very Unhealthy 2 of 365 days2018: Good 181 of 365 days2018: Moderate 173 of 365 days2018: Unhealthy for Sensitive Groups 10 of 365 days2018: Unhealthy 1 of 365 days20182019: Good 157 of 365 days2019: Moderate 186 of 365 days2019: Unhealthy for Sensitive Groups 17 of 365 days2019: Unhealthy 4 of 365 days2019: Very Unhealthy 1 of 365 days2020: Good 201 of 366 days2020: Moderate 160 of 366 days2020: Unhealthy for Sensitive Groups 5 of 366 days20202021: Good 190 of 365 days2021: Moderate 149 of 365 days2021: Unhealthy for Sensitive Groups 24 of 365 days2021: Unhealthy 2 of 365 days2022: Good 242 of 365 days2022: Moderate 123 of 365 days20222023: Good 154 of 365 days2023: Moderate 174 of 365 days2023: Unhealthy for Sensitive Groups 16 of 365 days2023: Unhealthy 18 of 365 days2023: Very Unhealthy 3 of 365 days2024: Good 218 of 366 days2024: Moderate 141 of 366 days2024: Unhealthy for Sensitive Groups 7 of 366 days20242025: Good 213 of 365 days2025: Moderate 148 of 365 days2025: Unhealthy for Sensitive Groups 4 of 365 days2025
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501001502001980: 90th percentile AQI 281983: 90th percentile AQI 492000: 90th percentile AQI 162001: 90th percentile AQI 112002: 90th percentile AQI 152003: 90th percentile AQI 122004: 90th percentile AQI 102005: 90th percentile AQI 132006: 90th percentile AQI 152007: 90th percentile AQI 642008: 90th percentile AQI 772009: 90th percentile AQI 672010: 90th percentile AQI 1262011: 90th percentile AQI 972012: 90th percentile AQI 902013: 90th percentile AQI 1642014: 90th percentile AQI 712015: 90th percentile AQI 672016: 90th percentile AQI 742017: 90th percentile AQI 742018: 90th percentile AQI 872019: 90th percentile AQI 872020: 90th percentile AQI 722021: 90th percentile AQI 932022: 90th percentile AQI 672023: 90th percentile AQI 1012024: 90th percentile AQI 772025: 90th percentile AQI 771980: Median AQI 191983: Median AQI 412000: Median AQI 52001: Median AQI 62002: Median AQI 62003: Median AQI 62004: Median AQI 52005: Median AQI 52006: Median AQI 62007: Median AQI 502008: Median AQI 512009: Median AQI 472010: Median AQI 542011: Median AQI 512012: Median AQI 542013: Median AQI 612014: Median AQI 482015: Median AQI 462016: Median AQI 472017: Median AQI 492018: Median AQI 512019: Median AQI 542020: Median AQI 502021: Median AQI 502022: Median AQI 472023: Median AQI 542024: Median AQI 482025: Median AQI 48198020002002200420062008201020122014201620182020202220242025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2025

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Ozone35196%
Fine particles (PM2.5)144%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536521314840004877126Ozone
202436621814170004877133Ozone
202336515417416183054101215Ozone
20223652421230000476793Ozone
2021365190149242005093159Ozone
202036620116050005072133Ozone
2019365157186174105487205Ozone
2018365181173101005187156Ozone
201736520015436204974206Ozone
201636623412145204774216Ozone
201536524212120004667122Ozone
201436522912862004871164Ozone
2013365126175222319061164238Ozone
2012366157193151005490167Ozone
20113651791541314505197236Ozone
2010365156162161813054126219Ozone
20092541728011004767190Ozone
200816676900000517797Ozone
200716396670000506493Ozone
200649490000061517PM10
200545450000051319PM10
200450500000051016PM10
200355550000061225PM10
200259590000061521PM10
200151510000061118PM10
200016160000051623PM10
1983178166120000414967Ozone
1980224223100001928100NO2

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

Counties in Utah with a similar median AQI in 2025

All monitored counties in Utah

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem