EnviroNearby

McClain County, Oklahoma air quality history

Daily Air Quality Index summaries from EPA monitors in McClain, Oklahoma, 1981–2025.

78%
Good days in 2025
43
Median daily AQI, 2025
1
Days above 100 in 2025
287
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for McClain, Oklahoma on 287 days. 225 of those days (78%) were in the Good range, and the median daily AQI was 43. That median is about the same as the typical monitored county in Oklahoma (median 44 across 19 counties), and higher than the typical monitored U.S. county (40). The main pollutant was ozone on 287 days. Across the years with fuller monitoring, the share of Good days fell: an average of 80% in 1983–1985 versus 67% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (287 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

Years with fewer than 120 monitored days (1981, 1982) 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%1981: Good 60 of 76 days1981: Moderate 15 of 76 days1981: Unhealthy for Sensitive Groups 1 of 76 days19811982: Good 31 of 31 days1983: Good 275 of 326 days1983: Moderate 41 of 326 days1983: Unhealthy for Sensitive Groups 10 of 326 days1984: Good 251 of 347 days1984: Moderate 59 of 347 days1984: Unhealthy for Sensitive Groups 32 of 347 days1984: Unhealthy 5 of 347 days1985: Good 220 of 268 days1985: Moderate 36 of 268 days1985: Unhealthy for Sensitive Groups 5 of 268 days1985: Unhealthy 7 of 268 days1986: Good 266 of 315 days1986: Moderate 44 of 315 days1986: Unhealthy for Sensitive Groups 5 of 315 days19861987: Good 258 of 344 days1987: Moderate 69 of 344 days1987: Unhealthy for Sensitive Groups 17 of 344 days1988: Good 260 of 352 days1988: Moderate 74 of 352 days1988: Unhealthy for Sensitive Groups 16 of 352 days1988: Unhealthy 2 of 352 days1989: Good 313 of 364 days1989: Moderate 46 of 364 days1989: Unhealthy for Sensitive Groups 5 of 364 days1990: Good 319 of 364 days1990: Moderate 43 of 364 days1990: Unhealthy for Sensitive Groups 2 of 364 days1991: Good 274 of 349 days1991: Moderate 67 of 349 days1991: Unhealthy for Sensitive Groups 8 of 349 days19911992: Good 308 of 356 days1992: Moderate 44 of 356 days1992: Unhealthy for Sensitive Groups 4 of 356 days1993: Good 326 of 352 days1993: Moderate 24 of 352 days1993: Unhealthy for Sensitive Groups 2 of 352 days1994: Good 321 of 364 days1994: Moderate 40 of 364 days1994: Unhealthy for Sensitive Groups 3 of 364 days1995: Good 269 of 352 days1995: Moderate 57 of 352 days1995: Unhealthy for Sensitive Groups 24 of 352 days1995: Unhealthy 2 of 352 days1996: Good 288 of 365 days1996: Moderate 70 of 365 days1996: Unhealthy for Sensitive Groups 7 of 365 days19961997: Good 301 of 364 days1997: Moderate 56 of 364 days1997: Unhealthy for Sensitive Groups 6 of 364 days1997: Unhealthy 1 of 364 days1998: Good 254 of 364 days1998: Moderate 80 of 364 days1998: Unhealthy for Sensitive Groups 26 of 364 days1998: Unhealthy 4 of 364 days1999: Good 282 of 343 days1999: Moderate 32 of 343 days1999: Unhealthy for Sensitive Groups 26 of 343 days1999: Unhealthy 3 of 343 days2000: Good 201 of 298 days2000: Moderate 70 of 298 days2000: Unhealthy for Sensitive Groups 25 of 298 days2000: Unhealthy 2 of 298 days2001: Good 268 of 365 days2001: Moderate 76 of 365 days2001: Unhealthy for Sensitive Groups 20 of 365 days2001: Unhealthy 1 of 365 days20012002: Good 291 of 365 days2002: Moderate 59 of 365 days2002: Unhealthy for Sensitive Groups 14 of 365 days2002: Unhealthy 1 of 365 days2003: Good 283 of 365 days2003: Moderate 70 of 365 days2003: Unhealthy for Sensitive Groups 11 of 365 days2003: Unhealthy 1 of 365 days2004: Good 328 of 361 days2004: Moderate 32 of 361 days2004: Unhealthy for Sensitive Groups 1 of 361 days2005: Good 301 of 364 days2005: Moderate 54 of 364 days2005: Unhealthy for Sensitive Groups 8 of 364 days2005: Unhealthy 1 of 364 days2006: Good 298 of 365 days2006: Moderate 51 of 365 days2006: Unhealthy for Sensitive Groups 16 of 365 days20062007: Good 334 of 363 days2007: Moderate 27 of 363 days2007: Unhealthy for Sensitive Groups 2 of 363 days2008: Good 293 of 361 days2008: Moderate 65 of 361 days2008: Unhealthy for Sensitive Groups 3 of 361 days2009: Good 295 of 363 days2009: Moderate 65 of 363 days2009: Unhealthy for Sensitive Groups 3 of 363 days2010: Good 316 of 362 days2010: Moderate 45 of 362 days2010: Unhealthy for Sensitive Groups 1 of 362 days2011: Good 254 of 365 days2011: Moderate 86 of 365 days2011: Unhealthy for Sensitive Groups 25 of 365 days20112012: Good 266 of 361 days2012: Moderate 82 of 361 days2012: Unhealthy for Sensitive Groups 12 of 361 days2012: Unhealthy 1 of 361 days2013: Good 288 of 335 days2013: Moderate 45 of 335 days2013: Unhealthy for Sensitive Groups 2 of 335 days2014: Good 300 of 351 days2014: Moderate 50 of 351 days2014: Unhealthy for Sensitive Groups 1 of 351 days2015: Good 322 of 359 days2015: Moderate 37 of 359 days2016: Good 335 of 362 days2016: Moderate 27 of 362 days20162017: Good 304 of 358 days2017: Moderate 52 of 358 days2017: Unhealthy for Sensitive Groups 2 of 358 days2018: Good 264 of 321 days2018: Moderate 54 of 321 days2018: Unhealthy for Sensitive Groups 3 of 321 days2021: Good 168 of 208 days2021: Moderate 39 of 208 days2021: Unhealthy for Sensitive Groups 1 of 208 days2022: Good 204 of 278 days2022: Moderate 71 of 278 days2022: Unhealthy for Sensitive Groups 3 of 278 days2023: Good 144 of 246 days2023: Moderate 91 of 246 days2023: Unhealthy for Sensitive Groups 11 of 246 days20232024: Good 172 of 269 days2024: Moderate 87 of 269 days2024: Unhealthy for Sensitive Groups 10 of 269 days2025: Good 225 of 287 days2025: Moderate 61 of 287 days2025: Unhealthy for Sensitive Groups 1 of 287 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 year0501001501981: 90th percentile AQI 671982: 90th percentile AQI 191983: 90th percentile AQI 611984: 90th percentile AQI 1011985: 90th percentile AQI 741986: 90th percentile AQI 711987: 90th percentile AQI 801988: 90th percentile AQI 901989: 90th percentile AQI 581990: 90th percentile AQI 541991: 90th percentile AQI 711992: 90th percentile AQI 581993: 90th percentile AQI 481994: 90th percentile AQI 541995: 90th percentile AQI 901996: 90th percentile AQI 671997: 90th percentile AQI 671998: 90th percentile AQI 971999: 90th percentile AQI 842000: 90th percentile AQI 1002001: 90th percentile AQI 932002: 90th percentile AQI 742003: 90th percentile AQI 772004: 90th percentile AQI 502005: 90th percentile AQI 712006: 90th percentile AQI 772007: 90th percentile AQI 492008: 90th percentile AQI 612009: 90th percentile AQI 612010: 90th percentile AQI 512011: 90th percentile AQI 902012: 90th percentile AQI 842013: 90th percentile AQI 582014: 90th percentile AQI 582015: 90th percentile AQI 512016: 90th percentile AQI 482017: 90th percentile AQI 642018: 90th percentile AQI 612021: 90th percentile AQI 612022: 90th percentile AQI 712023: 90th percentile AQI 872024: 90th percentile AQI 842025: 90th percentile AQI 671981: Median AQI 391982: Median AQI 141983: Median AQI 351984: Median AQI 391985: Median AQI 371986: Median AQI 341987: Median AQI 401988: Median AQI 401989: Median AQI 381990: Median AQI 341991: Median AQI 381992: Median AQI 371993: Median AQI 341994: Median AQI 361995: Median AQI 391996: Median AQI 381997: Median AQI 361998: Median AQI 401999: Median AQI 372000: Median AQI 442001: Median AQI 402002: Median AQI 362003: Median AQI 392004: Median AQI 332005: Median AQI 372006: Median AQI 392007: Median AQI 332008: Median AQI 382009: Median AQI 382010: Median AQI 372011: Median AQI 432012: Median AQI 392013: Median AQI 382014: Median AQI 392015: Median AQI 362016: Median AQI 372017: Median AQI 392018: Median AQI 382021: Median AQI 402022: Median AQI 452023: Median AQI 482024: Median AQI 462025: Median AQI 431981198619911996200120062011201620232025
  • 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
Ozone287100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20252872256110004367126Ozone
202426917287100004684133Ozone
202324614491110004887143Ozone
20222782047130004571119Ozone
20212081683910004061101Ozone
20183212645430003861119Ozone
20173583045220003964115Ozone
2016362335270000374887Ozone
2015359322370000365187Ozone
20143513005010003958108Ozone
20133352884520003858112Ozone
201236126682121003984164Ozone
201136525486250004390143Ozone
20103623164510003751108Ozone
20093632956530003861112Ozone
20083612936530003861119Ozone
20073633342720003349126Ozone
200636529851160003977147Ozone
20053643015481003771156Ozone
20043613283210003350133Ozone
200336528370111003977151Ozone
200236529159141003674164Ozone
200136526876201004093151Ozone
2000298201702520044100161Ozone
199934328232263003784182Ozone
199836425480264004097192Ozone
19973643015661003667161Ozone
19963652887070003867136Ozone
199535226957242003990161Ozone
19943643214030003654129Ozone
19933523262420003448115Ozone
19923563084440003758129Ozone
19913492746780003871143Ozone
19903643194320003454119Ozone
19893643134650003858115Ozone
198835226074162004090164Ozone
198734425869170004080133Ozone
19863152664450003471140Ozone
19852682203657003774197Ozone
1984347251593250039101164Ozone
198332627541100003561140Ozone
1982313100000141922Ozone
198176601510003967108Ozone

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 Oklahoma with a similar median AQI in 2025

All monitored counties in Oklahoma

Source: U.S. EPA AirData, “Annual AQI by County” files for 1981–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem