EnviroNearby

Sutter County, California air quality history

Daily Air Quality Index summaries from EPA monitors in Sutter, California, 1980–2025.

63%
Good days in 2025
47
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 Sutter, California on 364 days. 230 of those days (63%) were in the Good range, and the median daily AQI was 47. That median is about the same as 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 214 days. Across the years with fuller monitoring, the share of Good days rose: an average of 50% in 1982–1984 versus 56% in 2023–2025.

Years with fewer than 120 monitored days (1980, 1981) 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%1980: Good 45 of 45 days19801981: Good 52 of 59 days1981: Moderate 5 of 59 days1981: Unhealthy for Sensitive Groups 2 of 59 days1982: Good 190 of 286 days1982: Moderate 59 of 286 days1982: Unhealthy for Sensitive Groups 33 of 286 days1982: Unhealthy 4 of 286 days1983: Good 87 of 184 days1983: Moderate 66 of 184 days1983: Unhealthy for Sensitive Groups 26 of 184 days1983: Unhealthy 4 of 184 days1983: Very Unhealthy 1 of 184 days1984: Good 68 of 183 days1984: Moderate 61 of 183 days1984: Unhealthy for Sensitive Groups 40 of 183 days1984: Unhealthy 14 of 183 days1985: Good 106 of 207 days1985: Moderate 59 of 207 days1985: Unhealthy for Sensitive Groups 33 of 207 days1985: Unhealthy 9 of 207 days19851986: Good 145 of 265 days1986: Moderate 72 of 265 days1986: Unhealthy for Sensitive Groups 39 of 265 days1986: Unhealthy 9 of 265 days1987: Good 128 of 231 days1987: Moderate 65 of 231 days1987: Unhealthy for Sensitive Groups 32 of 231 days1987: Unhealthy 6 of 231 days1988: Good 160 of 272 days1988: Moderate 64 of 272 days1988: Unhealthy for Sensitive Groups 36 of 272 days1988: Unhealthy 12 of 272 days1989: Good 214 of 327 days1989: Moderate 91 of 327 days1989: Unhealthy for Sensitive Groups 20 of 327 days1989: Unhealthy 2 of 327 days1990: Good 278 of 355 days1990: Moderate 64 of 355 days1990: Unhealthy for Sensitive Groups 13 of 355 days19901991: Good 226 of 343 days1991: Moderate 89 of 343 days1991: Unhealthy for Sensitive Groups 26 of 343 days1991: Unhealthy 2 of 343 days1992: Good 213 of 366 days1992: Moderate 84 of 366 days1992: Unhealthy for Sensitive Groups 60 of 366 days1992: Unhealthy 8 of 366 days1992: Very Unhealthy 1 of 366 days1993: Good 255 of 365 days1993: Moderate 86 of 365 days1993: Unhealthy for Sensitive Groups 20 of 365 days1993: Unhealthy 3 of 365 days1993: Very Unhealthy 1 of 365 days1994: Good 186 of 365 days1994: Moderate 95 of 365 days1994: Unhealthy for Sensitive Groups 68 of 365 days1994: Unhealthy 16 of 365 days1995: Good 228 of 365 days1995: Moderate 85 of 365 days1995: Unhealthy for Sensitive Groups 37 of 365 days1995: Unhealthy 15 of 365 days19951996: Good 221 of 366 days1996: Moderate 68 of 366 days1996: Unhealthy for Sensitive Groups 51 of 366 days1996: Unhealthy 26 of 366 days1997: Good 261 of 365 days1997: Moderate 80 of 365 days1997: Unhealthy for Sensitive Groups 22 of 365 days1997: Unhealthy 2 of 365 days1998: Good 244 of 365 days1998: Moderate 67 of 365 days1998: Unhealthy for Sensitive Groups 38 of 365 days1998: Unhealthy 16 of 365 days1999: Good 193 of 365 days1999: Moderate 105 of 365 days1999: Unhealthy for Sensitive Groups 55 of 365 days1999: Unhealthy 12 of 365 days2000: Good 233 of 366 days2000: Moderate 101 of 366 days2000: Unhealthy for Sensitive Groups 28 of 366 days2000: Unhealthy 4 of 366 days20002001: Good 234 of 365 days2001: Moderate 102 of 365 days2001: Unhealthy for Sensitive Groups 26 of 365 days2001: Unhealthy 3 of 365 days2002: Good 216 of 365 days2002: Moderate 110 of 365 days2002: Unhealthy for Sensitive Groups 27 of 365 days2002: Unhealthy 12 of 365 days2003: Good 245 of 365 days2003: Moderate 83 of 365 days2003: Unhealthy for Sensitive Groups 32 of 365 days2003: Unhealthy 5 of 365 days2004: Good 198 of 366 days2004: Moderate 138 of 366 days2004: Unhealthy for Sensitive Groups 29 of 366 days2004: Unhealthy 1 of 366 days2005: Good 171 of 365 days2005: Moderate 166 of 365 days2005: Unhealthy for Sensitive Groups 28 of 365 days20052006: Good 130 of 365 days2006: Moderate 188 of 365 days2006: Unhealthy for Sensitive Groups 41 of 365 days2006: Unhealthy 6 of 365 days2007: Good 151 of 365 days2007: Moderate 181 of 365 days2007: Unhealthy for Sensitive Groups 32 of 365 days2007: Unhealthy 1 of 365 days2008: Good 150 of 365 days2008: Moderate 178 of 365 days2008: Unhealthy for Sensitive Groups 28 of 365 days2008: Unhealthy 6 of 365 days2008: Very Unhealthy 3 of 365 days2009: Good 134 of 365 days2009: Moderate 219 of 365 days2009: Unhealthy for Sensitive Groups 12 of 365 days2010: Good 163 of 365 days2010: Moderate 198 of 365 days2010: Unhealthy for Sensitive Groups 3 of 365 days2010: Unhealthy 1 of 365 days20102011: Good 92 of 365 days2011: Moderate 252 of 365 days2011: Unhealthy for Sensitive Groups 20 of 365 days2011: Unhealthy 1 of 365 days2012: Good 159 of 366 days2012: Moderate 190 of 366 days2012: Unhealthy for Sensitive Groups 17 of 366 days2013: Good 176 of 365 days2013: Moderate 180 of 365 days2013: Unhealthy for Sensitive Groups 9 of 365 days2014: Good 132 of 365 days2014: Moderate 220 of 365 days2014: Unhealthy for Sensitive Groups 12 of 365 days2014: Unhealthy 1 of 365 days2015: Good 157 of 365 days2015: Moderate 200 of 365 days2015: Unhealthy for Sensitive Groups 8 of 365 days20152016: Good 115 of 366 days2016: Moderate 219 of 366 days2016: Unhealthy for Sensitive Groups 32 of 366 days2017: Good 128 of 365 days2017: Moderate 228 of 365 days2017: Unhealthy for Sensitive Groups 9 of 365 days2018: Good 94 of 365 days2018: Moderate 236 of 365 days2018: Unhealthy for Sensitive Groups 22 of 365 days2018: Unhealthy 6 of 365 days2018: Very Unhealthy 6 of 365 days2018: Hazardous 1 of 365 days2019: Good 200 of 365 days2019: Moderate 163 of 365 days2019: Unhealthy for Sensitive Groups 2 of 365 days2020: Good 162 of 366 days2020: Moderate 173 of 366 days2020: Unhealthy for Sensitive Groups 15 of 366 days2020: Unhealthy 13 of 366 days2020: Very Unhealthy 2 of 366 days2020: Hazardous 1 of 366 days20202021: Good 102 of 364 days2021: Moderate 240 of 364 days2021: Unhealthy for Sensitive Groups 17 of 364 days2021: Unhealthy 5 of 364 days2022: Good 154 of 364 days2022: Moderate 205 of 364 days2022: Unhealthy for Sensitive Groups 5 of 364 days2023: Good 192 of 363 days2023: Moderate 168 of 363 days2023: Unhealthy for Sensitive Groups 3 of 363 days2024: Good 195 of 366 days2024: Moderate 166 of 366 days2024: Unhealthy for Sensitive Groups 5 of 366 days2025: Good 230 of 364 days2025: Moderate 134 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 year0501001501980: 90th percentile AQI 301981: 90th percentile AQI 541982: 90th percentile AQI 1051983: 90th percentile AQI 1081984: 90th percentile AQI 1361985: 90th percentile AQI 1191986: 90th percentile AQI 1261987: 90th percentile AQI 1151988: 90th percentile AQI 1221989: 90th percentile AQI 901990: 90th percentile AQI 711991: 90th percentile AQI 931992: 90th percentile AQI 1261993: 90th percentile AQI 871994: 90th percentile AQI 1331995: 90th percentile AQI 1151996: 90th percentile AQI 1401997: 90th percentile AQI 901998: 90th percentile AQI 1221999: 90th percentile AQI 1262000: 90th percentile AQI 1002001: 90th percentile AQI 972002: 90th percentile AQI 1012003: 90th percentile AQI 1012004: 90th percentile AQI 962005: 90th percentile AQI 932006: 90th percentile AQI 1082007: 90th percentile AQI 982008: 90th percentile AQI 1012009: 90th percentile AQI 842010: 90th percentile AQI 712011: 90th percentile AQI 902012: 90th percentile AQI 862013: 90th percentile AQI 842014: 90th percentile AQI 842015: 90th percentile AQI 862016: 90th percentile AQI 972017: 90th percentile AQI 842018: 90th percentile AQI 1002019: 90th percentile AQI 712020: 90th percentile AQI 902021: 90th percentile AQI 902022: 90th percentile AQI 812023: 90th percentile AQI 692024: 90th percentile AQI 802025: 90th percentile AQI 641980: Median AQI 211981: Median AQI 261982: Median AQI 421983: Median AQI 581984: Median AQI 671985: Median AQI 491986: Median AQI 481987: Median AQI 481988: Median AQI 441989: Median AQI 431990: Median AQI 371991: Median AQI 401992: Median AQI 471993: Median AQI 431994: Median AQI 491995: Median AQI 441996: Median AQI 451997: Median AQI 421998: Median AQI 431999: Median AQI 492000: Median AQI 432001: Median AQI 442002: Median AQI 452003: Median AQI 422004: Median AQI 472005: Median AQI 532006: Median AQI 582007: Median AQI 532008: Median AQI 562009: Median AQI 542010: Median AQI 522011: Median AQI 582012: Median AQI 532013: Median AQI 522014: Median AQI 552015: Median AQI 542016: Median AQI 582017: Median AQI 562018: Median AQI 582019: Median AQI 482020: Median AQI 532021: Median AQI 592022: Median AQI 522023: Median AQI 492024: Median AQI 492025: Median AQI 471980198519901995200020052010201520202025
  • 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
Ozone21459%
Fine particles (PM2.5)14941%
Coarse particles (PM10)1<1%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536423013400004764100Ozone
202436619516650004980115Ozone
202336319216830004969105Ozone
202236415420550005281119PM2.5
2021364102240175005990175PM2.5
20203661621731513215390356PM2.5
201936520016320004871110Ozone
2018365942362266158100420PM2.5
201736512822890005684130PM2.5
2016366115219320005897147PM2.5
201536515720080005486119PM2.5
2014365132220121005584156PM2.5
201336517618090005284126Ozone
2012366159190170005386150Ozone
201136592252201005890152PM2.5
201036516319831005271177PM2.5
2009365134219120005484125PM2.5
20083651501782863056101222PM2.5
2007365151181321005398151PM2.5
20063651301884160058108179Ozone
2005365171166280005393143Ozone
2004366198138291004796159Ozone
2003365245833250042101185Ozone
200236521611027120045101195Ozone
2001365234102263004497169Ozone
20003662331012840043100166Ozone
199936519310555120049126179Ozone
19983652446738160043122192Ozone
199736526180222004290166Ozone
19963662216851260045140192Ozone
19953652288537150044115195Ozone
19943651869568160049133187Ozone
199336525586203104387203Ozone
1992366213846081047126203Ozone
199134322689262004093174Ozone
199035527864130003771143Ozone
198932721491202004390154Ozone
19882721606436120044122192Ozone
1987231128653260048115174Ozone
1986265145723990048126195Ozone
1985207106593390049119179Ozone
1984183686140140067136190Ozone
198318487662641058108203Ozone
1982286190593340042105195Ozone
19815952520002654122Ozone
1980454500000213042Ozone

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 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