EnviroNearby

Madera County, California air quality history

Daily Air Quality Index summaries from EPA monitors in Madera, California, 1981–2025.

50%
Good days in 2025
50
Median daily AQI, 2025
3
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 Madera, California on 365 days. 184 of those days (50%) were in the Good range, and the median daily AQI was 50. That median is higher than the typical monitored county in California (median 45.5 across 46 counties), and higher than the typical monitored U.S. county (40). The main pollutant was ozone on 206 days. Across the years with fuller monitoring, the share of Good days rose: an average of 39% in 1981–1989 versus 46% in 2023–2025.

Years with fewer than 120 monitored days (1986, 1987, 1997) 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 27 of 133 days1981: Moderate 37 of 133 days1981: Unhealthy for Sensitive Groups 48 of 133 days1981: Unhealthy 20 of 133 days1981: Very Unhealthy 1 of 133 days19811986: Good 2 of 10 days1986: Moderate 7 of 10 days1986: Unhealthy for Sensitive Groups 1 of 10 days1987: Good 34 of 46 days1987: Moderate 12 of 46 days1988: Good 81 of 159 days1988: Moderate 45 of 159 days1988: Unhealthy for Sensitive Groups 25 of 159 days1988: Unhealthy 7 of 159 days1988: Very Unhealthy 1 of 159 days1989: Good 133 of 295 days1989: Moderate 99 of 295 days1989: Unhealthy for Sensitive Groups 50 of 295 days1989: Unhealthy 13 of 295 days1990: Good 162 of 252 days1990: Moderate 56 of 252 days1990: Unhealthy for Sensitive Groups 23 of 252 days1990: Unhealthy 11 of 252 days19901991: Good 186 of 352 days1991: Moderate 97 of 352 days1991: Unhealthy for Sensitive Groups 54 of 352 days1991: Unhealthy 15 of 352 days1992: Good 221 of 360 days1992: Moderate 78 of 360 days1992: Unhealthy for Sensitive Groups 51 of 360 days1992: Unhealthy 10 of 360 days1993: Good 189 of 357 days1993: Moderate 96 of 357 days1993: Unhealthy for Sensitive Groups 49 of 357 days1993: Unhealthy 20 of 357 days1993: Very Unhealthy 3 of 357 days1994: Good 241 of 359 days1994: Moderate 95 of 359 days1994: Unhealthy for Sensitive Groups 22 of 359 days1994: Unhealthy 1 of 359 days1995: Good 222 of 364 days1995: Moderate 90 of 364 days1995: Unhealthy for Sensitive Groups 39 of 364 days1995: Unhealthy 13 of 364 days19951996: Good 134 of 273 days1996: Moderate 66 of 273 days1996: Unhealthy for Sensitive Groups 48 of 273 days1996: Unhealthy 23 of 273 days1996: Very Unhealthy 2 of 273 days1997: Good 80 of 102 days1997: Moderate 19 of 102 days1997: Unhealthy for Sensitive Groups 3 of 102 days1998: Good 263 of 364 days1998: Moderate 56 of 364 days1998: Unhealthy for Sensitive Groups 33 of 364 days1998: Unhealthy 11 of 364 days1998: Very Unhealthy 1 of 364 days1999: Good 232 of 362 days1999: Moderate 86 of 362 days1999: Unhealthy for Sensitive Groups 34 of 362 days1999: Unhealthy 10 of 362 days2000: Good 217 of 362 days2000: Moderate 98 of 362 days2000: Unhealthy for Sensitive Groups 40 of 362 days2000: Unhealthy 7 of 362 days20002001: Good 213 of 359 days2001: Moderate 95 of 359 days2001: Unhealthy for Sensitive Groups 42 of 359 days2001: Unhealthy 9 of 359 days2002: Good 210 of 362 days2002: Moderate 89 of 362 days2002: Unhealthy for Sensitive Groups 48 of 362 days2002: Unhealthy 14 of 362 days2002: Very Unhealthy 1 of 362 days2003: Good 204 of 364 days2003: Moderate 96 of 364 days2003: Unhealthy for Sensitive Groups 51 of 364 days2003: Unhealthy 13 of 364 days2004: Good 214 of 340 days2004: Moderate 103 of 340 days2004: Unhealthy for Sensitive Groups 23 of 340 days2005: Good 265 of 362 days2005: Moderate 79 of 362 days2005: Unhealthy for Sensitive Groups 18 of 362 days20052006: Good 260 of 363 days2006: Moderate 72 of 363 days2006: Unhealthy for Sensitive Groups 30 of 363 days2006: Unhealthy 1 of 363 days2007: Good 279 of 363 days2007: Moderate 72 of 363 days2007: Unhealthy for Sensitive Groups 12 of 363 days2008: Good 215 of 346 days2008: Moderate 85 of 346 days2008: Unhealthy for Sensitive Groups 40 of 346 days2008: Unhealthy 5 of 346 days2008: Very Unhealthy 1 of 346 days2009: Good 262 of 365 days2009: Moderate 77 of 365 days2009: Unhealthy for Sensitive Groups 23 of 365 days2009: Unhealthy 3 of 365 days2010: Good 208 of 364 days2010: Moderate 128 of 364 days2010: Unhealthy for Sensitive Groups 18 of 364 days2010: Unhealthy 9 of 364 days2010: Very Unhealthy 1 of 364 days20102011: Good 20 of 365 days2011: Moderate 267 of 365 days2011: Unhealthy for Sensitive Groups 63 of 365 days2011: Unhealthy 15 of 365 days2012: Good 59 of 366 days2012: Moderate 226 of 366 days2012: Unhealthy for Sensitive Groups 70 of 366 days2012: Unhealthy 11 of 366 days2013: Good 31 of 365 days2013: Moderate 260 of 365 days2013: Unhealthy for Sensitive Groups 64 of 365 days2013: Unhealthy 10 of 365 days2014: Good 63 of 365 days2014: Moderate 227 of 365 days2014: Unhealthy for Sensitive Groups 60 of 365 days2014: Unhealthy 15 of 365 days2015: Good 78 of 365 days2015: Moderate 240 of 365 days2015: Unhealthy for Sensitive Groups 43 of 365 days2015: Unhealthy 4 of 365 days20152016: Good 91 of 366 days2016: Moderate 225 of 366 days2016: Unhealthy for Sensitive Groups 47 of 366 days2016: Unhealthy 3 of 366 days2017: Good 117 of 365 days2017: Moderate 200 of 365 days2017: Unhealthy for Sensitive Groups 42 of 365 days2017: Unhealthy 6 of 365 days2018: Good 122 of 365 days2018: Moderate 208 of 365 days2018: Unhealthy for Sensitive Groups 30 of 365 days2018: Unhealthy 5 of 365 days2019: Good 167 of 365 days2019: Moderate 185 of 365 days2019: Unhealthy for Sensitive Groups 13 of 365 days2020: Good 104 of 366 days2020: Moderate 209 of 366 days2020: Unhealthy for Sensitive Groups 34 of 366 days2020: Unhealthy 15 of 366 days2020: Very Unhealthy 4 of 366 days20202021: Good 133 of 365 days2021: Moderate 197 of 365 days2021: Unhealthy for Sensitive Groups 28 of 365 days2021: Unhealthy 7 of 365 days2022: Good 147 of 365 days2022: Moderate 205 of 365 days2022: Unhealthy for Sensitive Groups 13 of 365 days2023: Good 162 of 365 days2023: Moderate 188 of 365 days2023: Unhealthy for Sensitive Groups 14 of 365 days2023: Unhealthy 1 of 365 days2024: Good 163 of 366 days2024: Moderate 178 of 366 days2024: Unhealthy for Sensitive Groups 25 of 366 days2025: Good 184 of 365 days2025: Moderate 178 of 365 days2025: Unhealthy for Sensitive Groups 3 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 year0501001502001981: 90th percentile AQI 1641986: 90th percentile AQI 1111987: 90th percentile AQI 621988: 90th percentile AQI 1361989: 90th percentile AQI 1331990: 90th percentile AQI 1101991: 90th percentile AQI 1331992: 90th percentile AQI 1221993: 90th percentile AQI 1401994: 90th percentile AQI 901995: 90th percentile AQI 1151996: 90th percentile AQI 1501997: 90th percentile AQI 701998: 90th percentile AQI 1081999: 90th percentile AQI 1052000: 90th percentile AQI 1082001: 90th percentile AQI 1192002: 90th percentile AQI 1192003: 90th percentile AQI 1262004: 90th percentile AQI 932005: 90th percentile AQI 872006: 90th percentile AQI 972007: 90th percentile AQI 772008: 90th percentile AQI 1082009: 90th percentile AQI 902010: 90th percentile AQI 902011: 90th percentile AQI 1332012: 90th percentile AQI 1292013: 90th percentile AQI 1192014: 90th percentile AQI 1262015: 90th percentile AQI 1052016: 90th percentile AQI 1052017: 90th percentile AQI 1052018: 90th percentile AQI 1002019: 90th percentile AQI 842020: 90th percentile AQI 1132021: 90th percentile AQI 1002022: 90th percentile AQI 872023: 90th percentile AQI 842024: 90th percentile AQI 962025: 90th percentile AQI 761981: Median AQI 1011986: Median AQI 621987: Median AQI 401988: Median AQI 491989: Median AQI 541990: Median AQI 401991: Median AQI 481992: Median AQI 441993: Median AQI 481994: Median AQI 441995: Median AQI 431996: Median AQI 541997: Median AQI 351998: Median AQI 401999: Median AQI 442000: Median AQI 452001: Median AQI 462002: Median AQI 462003: Median AQI 462004: Median AQI 442005: Median AQI 402006: Median AQI 392007: Median AQI 402008: Median AQI 452009: Median AQI 402010: Median AQI 472011: Median AQI 742012: Median AQI 682013: Median AQI 722014: Median AQI 682015: Median AQI 642016: Median AQI 632017: Median AQI 622018: Median AQI 582019: Median AQI 522020: Median AQI 642021: Median AQI 582022: Median AQI 542023: Median AQI 522024: Median AQI 522025: Median AQI 50198119901995200020052010201520202025
  • 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
Ozone20656%
Fine particles (PM2.5)14439%
Coarse particles (PM10)154%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536518417830005076136Ozone
2024366163178250005296140Ozone
2023365162188141005284151Ozone
2022365147205130005487136Ozone
20213651331972870058100194Ozone
202036610420934154064113275PM2.5
2019365167185130005284140Ozone
20183651222083050058100169Ozone
20173651172004260062105166Ozone
2016366912254730063105156Ozone
2015365782404340064105156Ozone
20143656322760150068126179Ozone
20133653126064100072119190PM2.5
20123665922670110068129200PM2.5
20113652026763150074133179PM2.5
2010364208128189104790201Ozone
200936526277233004090177Ozone
2008346215854051045108202Ozone
200736327972120004077143Ozone
200636326072301003997174Ozone
200536226579180004087136Ozone
2004340214103230004493147Ozone
20033642049651130046126192Ozone
20023622108948141046119205Ozone
2001359213954290046119169Ozone
2000362217984070045108177Ozone
19993622328634100044105174Ozone
19983642635633111040108212Ozone
1997102801930003570133Ozone
19962731346648232054150206Ozone
19953642229039130043115192Ozone
199435924195221004490151Ozone
19933571899649203048140205Ozone
19923602217851100044122179Ozone
19913521869754150048133190Ozone
19902521625623110040110182Ozone
19892951339950130054133190Ozone
198815981452571049136201Ozone
19874634120000406273PM10
19861027100062111111PM10
19811332737482010101164213Ozone

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 California with a similar median AQI in 2025

All monitored counties in California

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