EnviroNearby

Amador County, California air quality history

Daily Air Quality Index summaries from EPA monitors in Amador, California, 1992–2025.

87%
Good days in 2025
38
Median daily AQI, 2025
0
Days above 100 in 2025
364
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Amador, California on 364 days. 318 of those days (87%) were in the Good range, and the median daily AQI was 38. That median is lower than the typical monitored county in California (median 45.5 across 46 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 364 days. Across the years with fuller monitoring, the share of Good days rose: an average of 59% in 1992–1994 versus 87% 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%1992: Good 126 of 245 days1992: Moderate 62 of 245 days1992: Unhealthy for Sensitive Groups 49 of 245 days1992: Unhealthy 8 of 245 days19921993: Good 238 of 364 days1993: Moderate 86 of 364 days1993: Unhealthy for Sensitive Groups 35 of 364 days1993: Unhealthy 5 of 364 days1994: Good 221 of 365 days1994: Moderate 83 of 365 days1994: Unhealthy for Sensitive Groups 48 of 365 days1994: Unhealthy 13 of 365 days1995: Good 239 of 365 days1995: Moderate 74 of 365 days1995: Unhealthy for Sensitive Groups 37 of 365 days1995: Unhealthy 14 of 365 days1995: Very Unhealthy 1 of 365 days1996: Good 236 of 366 days1996: Moderate 69 of 366 days1996: Unhealthy for Sensitive Groups 48 of 366 days1996: Unhealthy 12 of 366 days1996: Very Unhealthy 1 of 366 days1997: Good 270 of 365 days1997: Moderate 70 of 365 days1997: Unhealthy for Sensitive Groups 22 of 365 days1997: Unhealthy 3 of 365 days19971998: Good 272 of 365 days1998: Moderate 43 of 365 days1998: Unhealthy for Sensitive Groups 26 of 365 days1998: Unhealthy 20 of 365 days1998: Very Unhealthy 4 of 365 days1999: Good 212 of 365 days1999: Moderate 89 of 365 days1999: Unhealthy for Sensitive Groups 53 of 365 days1999: Unhealthy 10 of 365 days1999: Very Unhealthy 1 of 365 days2000: Good 238 of 366 days2000: Moderate 83 of 366 days2000: Unhealthy for Sensitive Groups 34 of 366 days2000: Unhealthy 11 of 366 days2001: Good 250 of 365 days2001: Moderate 89 of 365 days2001: Unhealthy for Sensitive Groups 25 of 365 days2001: Unhealthy 1 of 365 days2002: Good 237 of 360 days2002: Moderate 87 of 360 days2002: Unhealthy for Sensitive Groups 31 of 360 days2002: Unhealthy 5 of 360 days20022003: Good 257 of 365 days2003: Moderate 79 of 365 days2003: Unhealthy for Sensitive Groups 29 of 365 days2004: Good 250 of 366 days2004: Moderate 96 of 366 days2004: Unhealthy for Sensitive Groups 18 of 366 days2004: Unhealthy 2 of 366 days2005: Good 277 of 365 days2005: Moderate 66 of 365 days2005: Unhealthy for Sensitive Groups 18 of 365 days2005: Unhealthy 4 of 365 days2006: Good 265 of 364 days2006: Moderate 69 of 364 days2006: Unhealthy for Sensitive Groups 27 of 364 days2006: Unhealthy 3 of 364 days2007: Good 270 of 349 days2007: Moderate 69 of 349 days2007: Unhealthy for Sensitive Groups 10 of 349 days20072008: Good 220 of 353 days2008: Moderate 91 of 353 days2008: Unhealthy for Sensitive Groups 28 of 353 days2008: Unhealthy 11 of 353 days2008: Very Unhealthy 3 of 353 days2009: Good 298 of 362 days2009: Moderate 63 of 362 days2009: Unhealthy for Sensitive Groups 1 of 362 days2010: Good 302 of 361 days2010: Moderate 48 of 361 days2010: Unhealthy for Sensitive Groups 10 of 361 days2010: Unhealthy 1 of 361 days2011: Good 284 of 363 days2011: Moderate 76 of 363 days2011: Unhealthy for Sensitive Groups 3 of 363 days2012: Good 257 of 363 days2012: Moderate 86 of 363 days2012: Unhealthy for Sensitive Groups 19 of 363 days2012: Unhealthy 1 of 363 days20122013: Good 301 of 365 days2013: Moderate 62 of 365 days2013: Unhealthy for Sensitive Groups 2 of 365 days2014: Good 263 of 359 days2014: Moderate 86 of 359 days2014: Unhealthy for Sensitive Groups 10 of 359 days2015: Good 283 of 364 days2015: Moderate 73 of 364 days2015: Unhealthy for Sensitive Groups 8 of 364 days2016: Good 304 of 366 days2016: Moderate 57 of 366 days2016: Unhealthy for Sensitive Groups 5 of 366 days2017: Good 291 of 362 days2017: Moderate 67 of 362 days2017: Unhealthy for Sensitive Groups 4 of 362 days20172018: Good 288 of 364 days2018: Moderate 70 of 364 days2018: Unhealthy for Sensitive Groups 6 of 364 days2019: Good 308 of 355 days2019: Moderate 45 of 355 days2019: Unhealthy for Sensitive Groups 2 of 355 days2020: Good 327 of 359 days2020: Moderate 29 of 359 days2020: Unhealthy for Sensitive Groups 2 of 359 days2020: Unhealthy 1 of 359 days2021: Good 307 of 365 days2021: Moderate 54 of 365 days2021: Unhealthy for Sensitive Groups 4 of 365 days2022: Good 333 of 364 days2022: Moderate 30 of 364 days2022: Unhealthy for Sensitive Groups 1 of 364 days20222023: Good 341 of 360 days2023: Moderate 19 of 360 days2024: Good 281 of 359 days2024: Moderate 72 of 359 days2024: Unhealthy for Sensitive Groups 6 of 359 days2025: Good 318 of 364 days2025: Moderate 46 of 364 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 year0501001501992: 90th percentile AQI 1261993: 90th percentile AQI 1011994: 90th percentile AQI 1191995: 90th percentile AQI 1081996: 90th percentile AQI 1191997: 90th percentile AQI 901998: 90th percentile AQI 1151999: 90th percentile AQI 1222000: 90th percentile AQI 1122001: 90th percentile AQI 932002: 90th percentile AQI 1052003: 90th percentile AQI 972004: 90th percentile AQI 842005: 90th percentile AQI 872006: 90th percentile AQI 972007: 90th percentile AQI 712008: 90th percentile AQI 1152009: 90th percentile AQI 672010: 90th percentile AQI 642011: 90th percentile AQI 742012: 90th percentile AQI 902013: 90th percentile AQI 612014: 90th percentile AQI 802015: 90th percentile AQI 672016: 90th percentile AQI 642017: 90th percentile AQI 642018: 90th percentile AQI 712019: 90th percentile AQI 512020: 90th percentile AQI 502021: 90th percentile AQI 672022: 90th percentile AQI 502023: 90th percentile AQI 482024: 90th percentile AQI 742025: 90th percentile AQI 541992: Median AQI 481993: Median AQI 421994: Median AQI 441995: Median AQI 421996: Median AQI 411997: Median AQI 401998: Median AQI 371999: Median AQI 452000: Median AQI 442001: Median AQI 402002: Median AQI 422003: Median AQI 412004: Median AQI 412005: Median AQI 382006: Median AQI 372007: Median AQI 382008: Median AQI 452009: Median AQI 382010: Median AQI 352011: Median AQI 382012: Median AQI 402013: Median AQI 382014: Median AQI 422015: Median AQI 412016: Median AQI 372017: Median AQI 382018: Median AQI 402019: Median AQI 392020: Median AQI 372021: Median AQI 372022: Median AQI 362023: Median AQI 362024: Median AQI 402025: Median AQI 3819921997200220072012201720222025
  • 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
Ozone364100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025364318460000385497Ozone
20243592817260004074143Ozone
2023360341190000364880Ozone
20223643333010003650112Ozone
20213653075440003767133Ozone
20203593272921003750156Ozone
20193553084520003951115Ozone
20183642887060004071129Ozone
20173622916740003864136Ozone
20163663045750003764115Ozone
20153642837380004167140Ozone
201435926386100004280133Ozone
20133653016220003861108Ozone
201236325786191004090156Ozone
20113632847630003874119Ozone
201036130248101003564151Ozone
20093622986310003867122Ozone
20083532209128113045115206Ozone
200734927069100003871122Ozone
200636426569273003797185Ozone
200536527766184003887179Ozone
200436625096182004184156Ozone
200336525779290004197150Ozone
2002360237873150042105166Ozone
200136525089251004093154Ozone
20003662388334110044112192Ozone
19993652128953101045122202Ozone
19983652724326204037115210Ozone
199736527070223004090197Ozone
19963662366948121041119201Ozone
19953652397437141042108207Ozone
19943652218348130044119197Ozone
1993364238863550042101161Ozone
1992245126624980048126200Ozone

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 1992–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem