EnviroNearby

Polk County, Arkansas air quality history

Daily Air Quality Index summaries from EPA monitors in Polk, Arkansas, 1989–2025.

77%
Good days in 2025
41
Median daily AQI, 2025
1
Days above 100 in 2025
302
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Polk, Arkansas on 302 days. 234 of those days (77%) were in the Good range, and the median daily AQI was 41. That median is lower than the typical monitored county in Arkansas (median 46 across 11 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 213 days. Across the years with fuller monitoring, the share of Good days rose: an average of 35% in 2000–2003 versus 79% in 2023–2025.

Years with fewer than 120 monitored days (1994, 1995, 1996, 1997, 1999, 2002…) 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%1989: Good 31 of 31 days19891990: Good 55 of 55 days1991: Good 50 of 50 days1992: Good 53 of 54 days1992: Moderate 1 of 54 days1993: Good 53 of 55 days1993: Moderate 2 of 55 days1994: Good 55 of 55 days19941995: Good 53 of 54 days1995: Moderate 1 of 54 days1996: Good 56 of 57 days1996: Moderate 1 of 57 days1997: Good 51 of 52 days1997: Moderate 1 of 52 days1999: Good 11 of 24 days1999: Moderate 13 of 24 days2000: Good 36 of 125 days2000: Moderate 89 of 125 days20002001: Good 45 of 121 days2001: Moderate 76 of 121 days2002: Good 56 of 118 days2002: Moderate 62 of 118 days2003: Good 48 of 121 days2003: Moderate 73 of 121 days2004: Good 94 of 171 days2004: Moderate 77 of 171 days2005: Good 210 of 365 days2005: Moderate 137 of 365 days2005: Unhealthy for Sensitive Groups 18 of 365 days20052006: Good 202 of 365 days2006: Moderate 150 of 365 days2006: Unhealthy for Sensitive Groups 13 of 365 days2007: Good 225 of 364 days2007: Moderate 129 of 364 days2007: Unhealthy for Sensitive Groups 8 of 364 days2007: Unhealthy 2 of 364 days2008: Good 239 of 362 days2008: Moderate 121 of 362 days2008: Unhealthy for Sensitive Groups 2 of 362 days2009: Good 265 of 363 days2009: Moderate 95 of 363 days2009: Unhealthy for Sensitive Groups 3 of 363 days2010: Good 225 of 362 days2010: Moderate 128 of 362 days2010: Unhealthy for Sensitive Groups 9 of 362 days20102011: Good 200 of 364 days2011: Moderate 151 of 364 days2011: Unhealthy for Sensitive Groups 13 of 364 days2012: Good 229 of 361 days2012: Moderate 128 of 361 days2012: Unhealthy for Sensitive Groups 4 of 361 days2013: Good 261 of 354 days2013: Moderate 93 of 354 days2014: Good 278 of 360 days2014: Moderate 82 of 360 days2015: Good 286 of 361 days2015: Moderate 74 of 361 days2015: Unhealthy for Sensitive Groups 1 of 361 days20152016: Good 289 of 366 days2016: Moderate 77 of 366 days2017: Good 299 of 362 days2017: Moderate 63 of 362 days2018: Good 293 of 363 days2018: Moderate 70 of 363 days2019: Good 291 of 361 days2019: Moderate 69 of 361 days2019: Unhealthy for Sensitive Groups 1 of 361 days2020: Good 322 of 359 days2020: Moderate 37 of 359 days20202021: Good 299 of 360 days2021: Moderate 61 of 360 days2022: Good 308 of 350 days2022: Moderate 40 of 350 days2022: Unhealthy for Sensitive Groups 2 of 350 days2023: Good 188 of 242 days2023: Moderate 54 of 242 days2024: Good 261 of 324 days2024: Moderate 62 of 324 days2024: Unhealthy 1 of 324 days2025: Good 234 of 302 days2025: Moderate 67 of 302 days2025: Unhealthy for Sensitive Groups 1 of 302 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 year0501001989: 90th percentile AQI 301990: 90th percentile AQI 341991: 90th percentile AQI 391992: 90th percentile AQI 371993: 90th percentile AQI 351994: 90th percentile AQI 331995: 90th percentile AQI 371996: 90th percentile AQI 371997: 90th percentile AQI 291999: 90th percentile AQI 662000: 90th percentile AQI 722001: 90th percentile AQI 722002: 90th percentile AQI 732003: 90th percentile AQI 692004: 90th percentile AQI 642005: 90th percentile AQI 902006: 90th percentile AQI 812007: 90th percentile AQI 802008: 90th percentile AQI 672009: 90th percentile AQI 642010: 90th percentile AQI 742011: 90th percentile AQI 802012: 90th percentile AQI 732013: 90th percentile AQI 642014: 90th percentile AQI 592015: 90th percentile AQI 582016: 90th percentile AQI 572017: 90th percentile AQI 552018: 90th percentile AQI 572019: 90th percentile AQI 582020: 90th percentile AQI 512021: 90th percentile AQI 562022: 90th percentile AQI 522023: 90th percentile AQI 562024: 90th percentile AQI 562025: 90th percentile AQI 591989: Median AQI 191990: Median AQI 201991: Median AQI 211992: Median AQI 181993: Median AQI 201994: Median AQI 191995: Median AQI 221996: Median AQI 191997: Median AQI 181999: Median AQI 552000: Median AQI 572001: Median AQI 552002: Median AQI 522003: Median AQI 532004: Median AQI 452005: Median AQI 442006: Median AQI 482007: Median AQI 462008: Median AQI 442009: Median AQI 412010: Median AQI 452011: Median AQI 482012: Median AQI 442013: Median AQI 442014: Median AQI 392015: Median AQI 392016: Median AQI 412017: Median AQI 412018: Median AQI 402019: Median AQI 402020: Median AQI 372021: Median AQI 402022: Median AQI 342023: Median AQI 402024: Median AQI 382025: Median AQI 4119891994200020052010201520202025
  • 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
Ozone21371%
Fine particles (PM2.5)8929%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253022346710004159119Ozone
20243242616201003856167Ozone
2023242188540000405692Ozone
20223503084020003452105Ozone
2021360299610000405693Ozone
2020359322370000375184Ozone
20193612916910004058119Ozone
2018363293700000405793Ozone
2017362299630000415597Ozone
2016366289770000415787Ozone
20153612867410003958101Ozone
20143602788200003959100Ozone
2013354261930000446493Ozone
201236122912840004473133Ozone
2011364200151130004880150Ozone
201036222512890004574136Ozone
20093632659530004164108Ozone
200836223912120004467108Ozone
200736422512982004680166Ozone
2006365202150130004881122Ozone
2005365210137180004490129Ozone
200417194770000456480PM2.5
200312148730000536984PM2.5
200211856620000527398PM2.5
200112145760000557286PM2.5
200012536890000577287PM2.5
19992411130000556674PM2.5
1997525110000182957PM10
1996575610000193751PM10
1995545310000223753PM10
1994555500000193350PM10
1993555320000203557PM10
1992545310000183762PM10
1991505000000213948PM10
1990555500000203445PM10
1989313100000193047PM10

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 Arkansas with a similar median AQI in 2025

All monitored counties in Arkansas

Source: U.S. EPA AirData, “Annual AQI by County” files for 1989–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem