EnviroNearby

Rock Island County, Illinois air quality history

Daily Air Quality Index summaries from EPA monitors in Rock Island, Illinois, 1980–2025.

67%
Good days in 2025
41
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 Rock Island, Illinois on 365 days. 244 of those days (67%) were in the Good range, and the median daily AQI was 41. That median is about the same as the typical monitored county in Illinois (median 42 across 23 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 242 days. Across the years with fuller monitoring, the share of Good days fell: an average of 84% in 1980–1982 versus 64% 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 303 of 365 days1980: Moderate 53 of 365 days1980: Unhealthy for Sensitive Groups 8 of 365 days1980: Very Unhealthy 1 of 365 days19801981: Good 295 of 365 days1981: Moderate 67 of 365 days1981: Unhealthy for Sensitive Groups 3 of 365 days1982: Good 322 of 363 days1982: Moderate 40 of 363 days1982: Unhealthy for Sensitive Groups 1 of 363 days1983: Good 303 of 364 days1983: Moderate 54 of 364 days1983: Unhealthy for Sensitive Groups 6 of 364 days1983: Unhealthy 1 of 364 days1984: Good 290 of 339 days1984: Moderate 39 of 339 days1984: Unhealthy for Sensitive Groups 10 of 339 days1985: Good 298 of 365 days1985: Moderate 56 of 365 days1985: Unhealthy for Sensitive Groups 10 of 365 days1985: Unhealthy 1 of 365 days19851986: Good 313 of 363 days1986: Moderate 46 of 363 days1986: Unhealthy for Sensitive Groups 4 of 363 days1987: Good 302 of 365 days1987: Moderate 53 of 365 days1987: Unhealthy for Sensitive Groups 10 of 365 days1988: Good 253 of 366 days1988: Moderate 63 of 366 days1988: Unhealthy for Sensitive Groups 46 of 366 days1988: Unhealthy 4 of 366 days1989: Good 298 of 364 days1989: Moderate 50 of 364 days1989: Unhealthy for Sensitive Groups 16 of 364 days1990: Good 343 of 362 days1990: Moderate 19 of 362 days19901991: Good 302 of 342 days1991: Moderate 28 of 342 days1991: Unhealthy for Sensitive Groups 12 of 342 days1992: Good 332 of 357 days1992: Moderate 22 of 357 days1992: Unhealthy for Sensitive Groups 3 of 357 days1993: Good 349 of 361 days1993: Moderate 12 of 361 days1994: Good 322 of 363 days1994: Moderate 38 of 363 days1994: Unhealthy for Sensitive Groups 3 of 363 days1995: Good 329 of 362 days1995: Moderate 26 of 362 days1995: Unhealthy for Sensitive Groups 7 of 362 days19951996: Good 342 of 366 days1996: Moderate 20 of 366 days1996: Unhealthy for Sensitive Groups 4 of 366 days1997: Good 346 of 365 days1997: Moderate 17 of 365 days1997: Unhealthy for Sensitive Groups 2 of 365 days1998: Good 319 of 355 days1998: Moderate 32 of 355 days1998: Unhealthy for Sensitive Groups 4 of 355 days1999: Good 286 of 364 days1999: Moderate 71 of 364 days1999: Unhealthy for Sensitive Groups 7 of 364 days2000: Good 295 of 344 days2000: Moderate 49 of 344 days20002001: Good 251 of 332 days2001: Moderate 76 of 332 days2001: Unhealthy for Sensitive Groups 5 of 332 days2002: Good 245 of 314 days2002: Moderate 64 of 314 days2002: Unhealthy for Sensitive Groups 5 of 314 days2003: Good 294 of 365 days2003: Moderate 68 of 365 days2003: Unhealthy for Sensitive Groups 3 of 365 days2004: Good 327 of 366 days2004: Moderate 37 of 366 days2004: Unhealthy for Sensitive Groups 2 of 366 days2005: Good 296 of 365 days2005: Moderate 64 of 365 days2005: Unhealthy for Sensitive Groups 5 of 365 days20052006: Good 300 of 365 days2006: Moderate 62 of 365 days2006: Unhealthy for Sensitive Groups 3 of 365 days2007: Good 293 of 364 days2007: Moderate 66 of 364 days2007: Unhealthy for Sensitive Groups 5 of 364 days2008: Good 301 of 340 days2008: Moderate 39 of 340 days2009: Good 325 of 354 days2009: Moderate 29 of 354 days2010: Good 332 of 363 days2010: Moderate 31 of 363 days20102011: Good 358 of 365 days2011: Moderate 7 of 365 days2012: Good 331 of 359 days2012: Moderate 27 of 359 days2012: Unhealthy for Sensitive Groups 1 of 359 days2013: Good 320 of 335 days2013: Moderate 15 of 335 days2014: Good 311 of 349 days2014: Moderate 38 of 349 days2015: Good 308 of 365 days2015: Moderate 56 of 365 days2015: Unhealthy for Sensitive Groups 1 of 365 days20152016: Good 298 of 343 days2016: Moderate 44 of 343 days2016: Unhealthy for Sensitive Groups 1 of 343 days2017: Good 270 of 363 days2017: Moderate 93 of 363 days2018: Good 212 of 365 days2018: Moderate 152 of 365 days2018: Unhealthy for Sensitive Groups 1 of 365 days2019: Good 221 of 361 days2019: Moderate 138 of 361 days2019: Unhealthy for Sensitive Groups 2 of 361 days2020: Good 234 of 355 days2020: Moderate 120 of 355 days2020: Unhealthy for Sensitive Groups 1 of 355 days20202021: Good 191 of 361 days2021: Moderate 167 of 361 days2021: Unhealthy for Sensitive Groups 3 of 361 days2022: Good 214 of 360 days2022: Moderate 146 of 360 days2023: Good 178 of 365 days2023: Moderate 167 of 365 days2023: Unhealthy for Sensitive Groups 16 of 365 days2023: Unhealthy 3 of 365 days2023: Very Unhealthy 1 of 365 days2024: Good 277 of 366 days2024: Moderate 89 of 366 days2025: Good 244 of 365 days2025: Moderate 119 of 365 days2025: Unhealthy 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 611981: 90th percentile AQI 631982: 90th percentile AQI 541983: 90th percentile AQI 581984: 90th percentile AQI 711985: 90th percentile AQI 671986: 90th percentile AQI 541987: 90th percentile AQI 671988: 90th percentile AQI 1051989: 90th percentile AQI 801990: 90th percentile AQI 461991: 90th percentile AQI 581992: 90th percentile AQI 451993: 90th percentile AQI 441994: 90th percentile AQI 511995: 90th percentile AQI 501996: 90th percentile AQI 461997: 90th percentile AQI 471998: 90th percentile AQI 511999: 90th percentile AQI 712000: 90th percentile AQI 582001: 90th percentile AQI 722002: 90th percentile AQI 672003: 90th percentile AQI 662004: 90th percentile AQI 512005: 90th percentile AQI 612006: 90th percentile AQI 612007: 90th percentile AQI 622008: 90th percentile AQI 512009: 90th percentile AQI 482010: 90th percentile AQI 482011: 90th percentile AQI 442012: 90th percentile AQI 492013: 90th percentile AQI 472014: 90th percentile AQI 542015: 90th percentile AQI 552016: 90th percentile AQI 522017: 90th percentile AQI 612018: 90th percentile AQI 632019: 90th percentile AQI 632020: 90th percentile AQI 612021: 90th percentile AQI 662022: 90th percentile AQI 642023: 90th percentile AQI 772024: 90th percentile AQI 552025: 90th percentile AQI 611980: Median AQI 351981: Median AQI 371982: Median AQI 361983: Median AQI 361984: Median AQI 341985: Median AQI 331986: Median AQI 331987: Median AQI 311988: Median AQI 361989: Median AQI 341990: Median AQI 321991: Median AQI 311992: Median AQI 271993: Median AQI 271994: Median AQI 311995: Median AQI 301996: Median AQI 301997: Median AQI 301998: Median AQI 291999: Median AQI 372000: Median AQI 342001: Median AQI 382002: Median AQI 362003: Median AQI 342004: Median AQI 312005: Median AQI 352006: Median AQI 352007: Median AQI 352008: Median AQI 352009: Median AQI 292010: Median AQI 332011: Median AQI 312012: Median AQI 312013: Median AQI 322014: Median AQI 342015: Median AQI 362016: Median AQI 342017: Median AQI 422018: Median AQI 462019: Median AQI 452020: Median AQI 432021: Median AQI 492022: Median AQI 472023: Median AQI 512024: Median AQI 442025: Median AQI 411980198519901995200020052010201520202025
  • 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
Fine particles (PM2.5)24266%
Ozone12334%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536524411902004161167PM2.5
2024366277890000445584PM2.5
2023365178167163105177232PM2.5
20223602141460000476490PM2.5
202136119116730004966112PM2.5
202035523412010004361102PM2.5
201936122113820004563115PM2.5
201836521215210004663101PM2.5
2017363270930000426193Ozone
20163432984410003452108Ozone
20153653085610003655105Ozone
2014349311380000345474Ozone
2013335320150000324777Ozone
20123593312710003149101Ozone
201136535870000314474Ozone
2010363332310000334880Ozone
2009354325290000294895Ozone
2008340301390000355190Ozone
20073642936650003562133Ozone
20063653006230003561115Ozone
20053652966450003561136Ozone
20043663273720003151119Ozone
20033652946830003466147Ozone
20023142456450003667147Ozone
20013322517650003872140Ozone
20003442954900003458100Ozone
19993642867170003771143Ozone
19983553193240002951112Ozone
19973653461720003047101Ozone
19963663422040003046122Ozone
19953623292670003050126Ozone
19943633223830003151126Ozone
19933613491200002744100Ozone
19923573322230002745140Ozone
199134230228120003158136Ozone
1990362343190000324693Ozone
198936429850160003480150Ozone
1988366253634640036105172Ozone
198736530253100003167133Ozone
19863633134640003354133Ozone
198536529856101003367172Ozone
198433929039100003471143Ozone
19833643035461003658151Ozone
19823633224010003654119Ozone
19813652956730003763150CO
19803653035380103561207CO

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 Illinois with a similar median AQI in 2025

All monitored counties in Illinois

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