EnviroNearby

Coconino County, Arizona air quality history

Daily Air Quality Index summaries from EPA monitors in Coconino, Arizona, 1980–2025.

70%
Good days in 2025
46
Median daily AQI, 2025
2
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 Coconino, Arizona on 365 days. 256 of those days (70%) were in the Good range, and the median daily AQI was 46. That median is about the same as the typical monitored county in Arizona (median 47 across 13 counties), and higher than the typical monitored U.S. county (40). The main pollutant was ozone on 355 days. Across the years with fuller monitoring, the share of Good days fell: an average of 76% in 1980–1982 versus 68% in 2023–2025.

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 228 of 283 days1980: Moderate 54 of 283 days1980: Unhealthy for Sensitive Groups 1 of 283 days19801981: Good 277 of 335 days1981: Moderate 54 of 335 days1981: Unhealthy for Sensitive Groups 4 of 335 days1982: Good 213 of 330 days1982: Moderate 83 of 330 days1982: Unhealthy for Sensitive Groups 31 of 330 days1982: Unhealthy 3 of 330 days1983: Good 243 of 328 days1983: Moderate 77 of 328 days1983: Unhealthy for Sensitive Groups 8 of 328 days1984: Good 276 of 342 days1984: Moderate 61 of 342 days1984: Unhealthy for Sensitive Groups 5 of 342 days1985: Good 290 of 360 days1985: Moderate 69 of 360 days1985: Unhealthy for Sensitive Groups 1 of 360 days19851986: Good 190 of 212 days1986: Moderate 22 of 212 days1987: Good 193 of 203 days1987: Moderate 10 of 203 days1988: Good 185 of 187 days1988: Moderate 2 of 187 days1989: Good 170 of 236 days1989: Moderate 66 of 236 days1990: Good 250 of 364 days1990: Moderate 107 of 364 days1990: Unhealthy for Sensitive Groups 7 of 364 days19901991: Good 248 of 362 days1991: Moderate 103 of 362 days1991: Unhealthy for Sensitive Groups 11 of 362 days1992: Good 268 of 365 days1992: Moderate 90 of 365 days1992: Unhealthy for Sensitive Groups 7 of 365 days1993: Good 281 of 362 days1993: Moderate 81 of 362 days1994: Good 233 of 363 days1994: Moderate 122 of 363 days1994: Unhealthy for Sensitive Groups 8 of 363 days1995: Good 233 of 362 days1995: Moderate 128 of 362 days1995: Unhealthy for Sensitive Groups 1 of 362 days19951996: Good 219 of 348 days1996: Moderate 120 of 348 days1996: Unhealthy for Sensitive Groups 9 of 348 days1997: Good 243 of 354 days1997: Moderate 107 of 354 days1997: Unhealthy for Sensitive Groups 4 of 354 days1998: Good 219 of 363 days1998: Moderate 136 of 363 days1998: Unhealthy for Sensitive Groups 8 of 363 days1999: Good 209 of 361 days1999: Moderate 137 of 361 days1999: Unhealthy for Sensitive Groups 15 of 361 days2000: Good 223 of 364 days2000: Moderate 136 of 364 days2000: Unhealthy for Sensitive Groups 5 of 364 days20002001: Good 233 of 359 days2001: Moderate 123 of 359 days2001: Unhealthy for Sensitive Groups 3 of 359 days2002: Good 193 of 359 days2002: Moderate 141 of 359 days2002: Unhealthy for Sensitive Groups 25 of 359 days2003: Good 203 of 359 days2003: Moderate 147 of 359 days2003: Unhealthy for Sensitive Groups 9 of 359 days2004: Good 233 of 362 days2004: Moderate 123 of 362 days2004: Unhealthy for Sensitive Groups 6 of 362 days2005: Good 238 of 358 days2005: Moderate 110 of 358 days2005: Unhealthy for Sensitive Groups 9 of 358 days2005: Unhealthy 1 of 358 days20052006: Good 208 of 361 days2006: Moderate 150 of 361 days2006: Unhealthy for Sensitive Groups 3 of 361 days2007: Good 200 of 357 days2007: Moderate 155 of 357 days2007: Unhealthy for Sensitive Groups 2 of 357 days2008: Good 240 of 365 days2008: Moderate 113 of 365 days2008: Unhealthy for Sensitive Groups 12 of 365 days2009: Good 253 of 363 days2009: Moderate 110 of 363 days2010: Good 230 of 363 days2010: Moderate 129 of 363 days2010: Unhealthy for Sensitive Groups 4 of 363 days20102011: Good 227 of 365 days2011: Moderate 128 of 365 days2011: Unhealthy for Sensitive Groups 10 of 365 days2012: Good 230 of 366 days2012: Moderate 121 of 366 days2012: Unhealthy for Sensitive Groups 15 of 366 days2013: Good 257 of 364 days2013: Moderate 104 of 364 days2013: Unhealthy for Sensitive Groups 3 of 364 days2014: Good 247 of 357 days2014: Moderate 105 of 357 days2014: Unhealthy for Sensitive Groups 5 of 357 days2015: Good 258 of 365 days2015: Moderate 103 of 365 days2015: Unhealthy for Sensitive Groups 4 of 365 days20152016: Good 298 of 366 days2016: Moderate 68 of 366 days2017: Good 253 of 365 days2017: Moderate 111 of 365 days2017: Unhealthy for Sensitive Groups 1 of 365 days2018: Good 236 of 365 days2018: Moderate 126 of 365 days2018: Unhealthy for Sensitive Groups 3 of 365 days2019: Good 280 of 365 days2019: Moderate 85 of 365 days2020: Good 302 of 366 days2020: Moderate 64 of 366 days20202021: Good 265 of 365 days2021: Moderate 100 of 365 days2022: Good 279 of 365 days2022: Moderate 85 of 365 days2022: Unhealthy for Sensitive Groups 1 of 365 days2023: Good 243 of 365 days2023: Moderate 118 of 365 days2023: Unhealthy for Sensitive Groups 1 of 365 days2023: Unhealthy 2 of 365 days2023: Very Unhealthy 1 of 365 days2024: Good 250 of 366 days2024: Moderate 111 of 366 days2024: Unhealthy for Sensitive Groups 5 of 366 days2025: Good 256 of 365 days2025: Moderate 107 of 365 days2025: Unhealthy for Sensitive Groups 2 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 year0501001501980: 90th percentile AQI 591981: 90th percentile AQI 581982: 90th percentile AQI 1011983: 90th percentile AQI 801984: 90th percentile AQI 671985: 90th percentile AQI 611986: 90th percentile AQI 511987: 90th percentile AQI 391988: 90th percentile AQI 331989: 90th percentile AQI 671990: 90th percentile AQI 711991: 90th percentile AQI 741992: 90th percentile AQI 711993: 90th percentile AQI 671994: 90th percentile AQI 771995: 90th percentile AQI 771996: 90th percentile AQI 771997: 90th percentile AQI 711998: 90th percentile AQI 841999: 90th percentile AQI 842000: 90th percentile AQI 802001: 90th percentile AQI 712002: 90th percentile AQI 932003: 90th percentile AQI 842004: 90th percentile AQI 742005: 90th percentile AQI 802006: 90th percentile AQI 842007: 90th percentile AQI 802008: 90th percentile AQI 842009: 90th percentile AQI 672010: 90th percentile AQI 742011: 90th percentile AQI 772012: 90th percentile AQI 802013: 90th percentile AQI 712014: 90th percentile AQI 672015: 90th percentile AQI 742016: 90th percentile AQI 612017: 90th percentile AQI 712018: 90th percentile AQI 772019: 90th percentile AQI 612020: 90th percentile AQI 582021: 90th percentile AQI 642022: 90th percentile AQI 642023: 90th percentile AQI 802024: 90th percentile AQI 742025: 90th percentile AQI 711980: Median AQI 401981: Median AQI 371982: Median AQI 411983: Median AQI 371984: Median AQI 61985: Median AQI 401986: Median AQI 221987: Median AQI 181988: Median AQI 171989: Median AQI 421990: Median AQI 461991: Median AQI 451992: Median AQI 441993: Median AQI 441994: Median AQI 481995: Median AQI 481996: Median AQI 471997: Median AQI 461998: Median AQI 481999: Median AQI 492000: Median AQI 472001: Median AQI 472002: Median AQI 492003: Median AQI 492004: Median AQI 472005: Median AQI 472006: Median AQI 482007: Median AQI 492008: Median AQI 482009: Median AQI 462010: Median AQI 472011: Median AQI 472012: Median AQI 472013: Median AQI 462014: Median AQI 442015: Median AQI 442016: Median AQI 442017: Median AQI 462018: Median AQI 452019: Median AQI 452020: Median AQI 442021: Median AQI 462022: Median AQI 442023: Median AQI 462024: Median AQI 462025: Median AQI 461980198519901995200020052010201520202025
  • 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
Ozone35597%
Fine particles (PM2.5)103%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536525610720004671113Ozone
202436625011150004674136Ozone
202336524311812104680203Ozone
20223652798510004464101Ozone
20213652651000000466493Ozone
2020366302640000445893Ozone
2019365280850000456180Ozone
201836523612630004577126Ozone
201736525311110004671105Ozone
2016366298680000446197Ozone
201536525810340004474108Ozone
201435724710550004467126Ozone
201336425710430004671115Ozone
2012366230121150004780133Ozone
2011365227128100004777129Ozone
201036323012940004774136Ozone
200936325311000004667100Ozone
2008365240113120004884129Ozone
200735720015520004980131Ozone
200636120815030004884122Ozone
200535823811091004780159Ozone
200436223312360004774122Ozone
200335920314790004984126Ozone
2002359193141250004993136Ozone
200135923312330004771105Ozone
200036422313650004780126Ozone
1999361209137150004984136Ozone
199836321913680004884108Ozone
199735424310740004671112Ozone
199634821912090004777129Ozone
199536223312810004877101Ozone
199436323312280004877119Ozone
1993362281810000446790Ozone
19923652689070004471126Ozone
1991362248103110004574122Ozone
199036425010770004671108Ozone
19892361706600004267100Ozone
198818718520000173351CO
1987203193100000183972CO
1986212190220000225173CO
19853602906910004061105Ozone
1984342276615000667129CO
19833282437780003780133Ozone
1982330213833130041101154Ozone
19813352775440003758115CO
19802832285410004059101CO

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 Arizona with a similar median AQI in 2025

All monitored counties in Arizona

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