EnviroNearby

Pima County, Arizona air quality history

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

34%
Good days in 2025
54
Median daily AQI, 2025
8
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 Pima, Arizona on 365 days. 123 of those days (34%) were in the Good range, and the median daily AQI was 54. That median is higher than 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 186 days. Across the years with fuller monitoring, the share of Good days rose: an average of 7% in 1980–1982 versus 33% 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 23 of 366 days1980: Moderate 223 of 366 days1980: Unhealthy for Sensitive Groups 118 of 366 days1980: Unhealthy 2 of 366 days19801981: Good 15 of 365 days1981: Moderate 279 of 365 days1981: Unhealthy for Sensitive Groups 70 of 365 days1981: Unhealthy 1 of 365 days1982: Good 38 of 365 days1982: Moderate 243 of 365 days1982: Unhealthy for Sensitive Groups 80 of 365 days1982: Unhealthy 4 of 365 days1983: Good 48 of 365 days1983: Moderate 250 of 365 days1983: Unhealthy for Sensitive Groups 64 of 365 days1983: Unhealthy 3 of 365 days1984: Good 59 of 366 days1984: Moderate 275 of 366 days1984: Unhealthy for Sensitive Groups 32 of 366 days1985: Good 59 of 365 days1985: Moderate 255 of 365 days1985: Unhealthy for Sensitive Groups 48 of 365 days1985: Unhealthy 3 of 365 days19851986: Good 92 of 365 days1986: Moderate 257 of 365 days1986: Unhealthy for Sensitive Groups 16 of 365 days1987: Good 163 of 365 days1987: Moderate 180 of 365 days1987: Unhealthy for Sensitive Groups 22 of 365 days1988: Good 158 of 366 days1988: Moderate 186 of 366 days1988: Unhealthy for Sensitive Groups 20 of 366 days1988: Unhealthy 2 of 366 days1989: Good 78 of 365 days1989: Moderate 267 of 365 days1989: Unhealthy for Sensitive Groups 20 of 365 days1990: Good 99 of 365 days1990: Moderate 236 of 365 days1990: Unhealthy for Sensitive Groups 29 of 365 days1990: Unhealthy 1 of 365 days19901991: Good 131 of 365 days1991: Moderate 218 of 365 days1991: Unhealthy for Sensitive Groups 16 of 365 days1992: Good 162 of 366 days1992: Moderate 184 of 366 days1992: Unhealthy for Sensitive Groups 19 of 366 days1992: Unhealthy 1 of 366 days1993: Good 151 of 365 days1993: Moderate 183 of 365 days1993: Unhealthy for Sensitive Groups 30 of 365 days1993: Unhealthy 1 of 365 days1994: Good 151 of 365 days1994: Moderate 184 of 365 days1994: Unhealthy for Sensitive Groups 30 of 365 days1995: Good 169 of 365 days1995: Moderate 168 of 365 days1995: Unhealthy for Sensitive Groups 25 of 365 days1995: Unhealthy 3 of 365 days19951996: Good 175 of 366 days1996: Moderate 174 of 366 days1996: Unhealthy for Sensitive Groups 17 of 366 days1997: Good 205 of 365 days1997: Moderate 144 of 365 days1997: Unhealthy for Sensitive Groups 16 of 365 days1998: Good 193 of 365 days1998: Moderate 148 of 365 days1998: Unhealthy for Sensitive Groups 24 of 365 days1999: Good 101 of 365 days1999: Moderate 247 of 365 days1999: Unhealthy for Sensitive Groups 16 of 365 days1999: Unhealthy 1 of 365 days2000: Good 164 of 366 days2000: Moderate 179 of 366 days2000: Unhealthy for Sensitive Groups 23 of 366 days20002001: Good 207 of 365 days2001: Moderate 154 of 365 days2001: Unhealthy for Sensitive Groups 4 of 365 days2002: Good 171 of 365 days2002: Moderate 183 of 365 days2002: Unhealthy for Sensitive Groups 10 of 365 days2002: Unhealthy 1 of 365 days2003: Good 140 of 365 days2003: Moderate 194 of 365 days2003: Unhealthy for Sensitive Groups 30 of 365 days2003: Unhealthy 1 of 365 days2004: Good 212 of 366 days2004: Moderate 145 of 366 days2004: Unhealthy for Sensitive Groups 9 of 366 days2005: Good 180 of 365 days2005: Moderate 167 of 365 days2005: Unhealthy for Sensitive Groups 16 of 365 days2005: Unhealthy 2 of 365 days20052006: Good 184 of 365 days2006: Moderate 162 of 365 days2006: Unhealthy for Sensitive Groups 19 of 365 days2007: Good 165 of 365 days2007: Moderate 189 of 365 days2007: Unhealthy for Sensitive Groups 11 of 365 days2008: Good 193 of 366 days2008: Moderate 156 of 366 days2008: Unhealthy for Sensitive Groups 17 of 366 days2009: Good 204 of 365 days2009: Moderate 159 of 365 days2009: Unhealthy for Sensitive Groups 1 of 365 days2009: Unhealthy 1 of 365 days2010: Good 204 of 365 days2010: Moderate 156 of 365 days2010: Unhealthy for Sensitive Groups 5 of 365 days20102011: Good 166 of 365 days2011: Moderate 179 of 365 days2011: Unhealthy for Sensitive Groups 20 of 365 days2012: Good 164 of 366 days2012: Moderate 193 of 366 days2012: Unhealthy for Sensitive Groups 9 of 366 days2013: Good 187 of 365 days2013: Moderate 170 of 365 days2013: Unhealthy for Sensitive Groups 5 of 365 days2013: Very Unhealthy 2 of 365 days2013: Hazardous 1 of 365 days2014: Good 197 of 365 days2014: Moderate 165 of 365 days2014: Unhealthy for Sensitive Groups 3 of 365 days2015: Good 236 of 365 days2015: Moderate 128 of 365 days2015: Unhealthy for Sensitive Groups 1 of 365 days20152016: Good 191 of 366 days2016: Moderate 171 of 366 days2016: Unhealthy for Sensitive Groups 4 of 366 days2017: Good 121 of 365 days2017: Moderate 237 of 365 days2017: Unhealthy for Sensitive Groups 7 of 365 days2018: Good 164 of 365 days2018: Moderate 190 of 365 days2018: Unhealthy for Sensitive Groups 11 of 365 days2019: Good 207 of 365 days2019: Moderate 156 of 365 days2019: Unhealthy for Sensitive Groups 2 of 365 days2020: Good 124 of 366 days2020: Moderate 229 of 366 days2020: Unhealthy for Sensitive Groups 12 of 366 days2020: Very Unhealthy 1 of 366 days20202021: Good 93 of 365 days2021: Moderate 258 of 365 days2021: Unhealthy for Sensitive Groups 13 of 365 days2021: Hazardous 1 of 365 days2022: Good 147 of 365 days2022: Moderate 205 of 365 days2022: Unhealthy for Sensitive Groups 13 of 365 days2023: Good 123 of 365 days2023: Moderate 235 of 365 days2023: Unhealthy for Sensitive Groups 7 of 365 days2024: Good 113 of 366 days2024: Moderate 241 of 366 days2024: Unhealthy for Sensitive Groups 10 of 366 days2024: Unhealthy 2 of 366 days2025: Good 123 of 365 days2025: Moderate 234 of 365 days2025: Unhealthy for Sensitive Groups 3 of 365 days2025: Unhealthy 3 of 365 days2025: Very Unhealthy 1 of 365 days2025: Hazardous 1 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 1161981: 90th percentile AQI 1061982: 90th percentile AQI 1151983: 90th percentile AQI 1081984: 90th percentile AQI 1001985: 90th percentile AQI 1121986: 90th percentile AQI 901987: 90th percentile AQI 901988: 90th percentile AQI 841989: 90th percentile AQI 901990: 90th percentile AQI 971991: 90th percentile AQI 841992: 90th percentile AQI 901993: 90th percentile AQI 1001994: 90th percentile AQI 1001995: 90th percentile AQI 931996: 90th percentile AQI 871997: 90th percentile AQI 901998: 90th percentile AQI 971999: 90th percentile AQI 872000: 90th percentile AQI 902001: 90th percentile AQI 772002: 90th percentile AQI 802003: 90th percentile AQI 972004: 90th percentile AQI 872005: 90th percentile AQI 842006: 90th percentile AQI 902007: 90th percentile AQI 842008: 90th percentile AQI 902009: 90th percentile AQI 712010: 90th percentile AQI 802011: 90th percentile AQI 902012: 90th percentile AQI 842013: 90th percentile AQI 802014: 90th percentile AQI 742015: 90th percentile AQI 712016: 90th percentile AQI 742017: 90th percentile AQI 802018: 90th percentile AQI 842019: 90th percentile AQI 712020: 90th percentile AQI 772021: 90th percentile AQI 852022: 90th percentile AQI 812023: 90th percentile AQI 842024: 90th percentile AQI 872025: 90th percentile AQI 801980: Median AQI 831981: Median AQI 801982: Median AQI 811983: Median AQI 741984: Median AQI 691985: Median AQI 671986: Median AQI 611987: Median AQI 531988: Median AQI 521989: Median AQI 611990: Median AQI 591991: Median AQI 551992: Median AQI 531993: Median AQI 521994: Median AQI 551995: Median AQI 511996: Median AQI 511997: Median AQI 491998: Median AQI 491999: Median AQI 582000: Median AQI 522001: Median AQI 492002: Median AQI 512003: Median AQI 542004: Median AQI 482005: Median AQI 512006: Median AQI 502007: Median AQI 522008: Median AQI 502009: Median AQI 492010: Median AQI 492011: Median AQI 512012: Median AQI 512013: Median AQI 502014: Median AQI 502015: Median AQI 462016: Median AQI 502017: Median AQI 542018: Median AQI 522019: Median AQI 492020: Median AQI 552021: Median AQI 562022: Median AQI 532023: Median AQI 542024: Median AQI 562025: Median AQI 541980198519901995200020052010201520202025
  • 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
Ozone18651%
Fine particles (PM2.5)11231%
Coarse particles (PM10)6718%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536512323433115480357Ozone
2024366113241102005687171Ozone
202336512323570005484147Ozone
2022365147205130005381142Ozone
202136593258130015685313Ozone
2020366124229120105577277Ozone
201936520715620004971103Ozone
2018365164190110005284129Ozone
201736512123770005480122Ozone
201636619117140005074119Ozone
201536523612810004671101Ozone
201436519716530005074129Ozone
201336518717050215080311Ozone
201236616419390005184143Ozone
2011365166179200005190144Ozone
201036520415650004980141Ozone
200936520415911004971158Ozone
2008366193156170005090133Ozone
2007365165189110005284127Ozone
2006365184162190005090143Ozone
2005365180167162005184154Ozone
200436621214590004887115Ozone
2003365140194301005497154Ozone
2002365171183101005180161Ozone
200136520715440004977115Ozone
2000366164179230005290136Ozone
1999365101247161005887151Ozone
1998365193148240004997133Ozone
1997365205144160004990150Ozone
1996366175174170005187147Ozone
1995365169168253005193166Ozone
19943651511843000055100150Ozone
19933651511833010052100156Ozone
1992366162184191005390159Ozone
1991365131218160005584143Ozone
199036599236291005997151Ozone
198936578267200006190129Ozone
1988366158186202005284176Ozone
1987365163180220005390150Ozone
198636592257160006190133Ozone
1985365592554830067112169CO
1984366592753200069100150CO
1983365482506430074108174CO
1982365382438040081115187CO
1981365152797010080106177NO2
19803662322311820083116161NO2

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