EnviroNearby

Ventura County, California air quality history

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

52%
Good days in 2025
50
Median daily AQI, 2025
8
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 Ventura, California on 365 days. 190 of those days (52%) 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 202 days. Across the years with fuller monitoring, the share of Good days rose: an average of 27% in 1980–1982 versus 55% 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%1980: Good 93 of 365 days1980: Moderate 111 of 365 days1980: Unhealthy for Sensitive Groups 50 of 365 days1980: Unhealthy 58 of 365 days1980: Very Unhealthy 53 of 365 days19801981: Good 112 of 362 days1981: Moderate 96 of 362 days1981: Unhealthy for Sensitive Groups 45 of 362 days1981: Unhealthy 74 of 362 days1981: Very Unhealthy 35 of 362 days1982: Good 91 of 365 days1982: Moderate 99 of 365 days1982: Unhealthy for Sensitive Groups 61 of 365 days1982: Unhealthy 60 of 365 days1982: Very Unhealthy 54 of 365 days1983: Good 137 of 365 days1983: Moderate 73 of 365 days1983: Unhealthy for Sensitive Groups 60 of 365 days1983: Unhealthy 48 of 365 days1983: Very Unhealthy 47 of 365 days1984: Good 102 of 366 days1984: Moderate 107 of 366 days1984: Unhealthy for Sensitive Groups 52 of 366 days1984: Unhealthy 64 of 366 days1984: Very Unhealthy 41 of 366 days1985: Good 117 of 365 days1985: Moderate 91 of 365 days1985: Unhealthy for Sensitive Groups 67 of 365 days1985: Unhealthy 58 of 365 days1985: Very Unhealthy 32 of 365 days19851986: Good 79 of 365 days1986: Moderate 103 of 365 days1986: Unhealthy for Sensitive Groups 74 of 365 days1986: Unhealthy 61 of 365 days1986: Very Unhealthy 48 of 365 days1987: Good 116 of 365 days1987: Moderate 89 of 365 days1987: Unhealthy for Sensitive Groups 78 of 365 days1987: Unhealthy 56 of 365 days1987: Very Unhealthy 26 of 365 days1988: Good 88 of 366 days1988: Moderate 102 of 366 days1988: Unhealthy for Sensitive Groups 69 of 366 days1988: Unhealthy 65 of 366 days1988: Very Unhealthy 42 of 366 days1989: Good 101 of 365 days1989: Moderate 107 of 365 days1989: Unhealthy for Sensitive Groups 70 of 365 days1989: Unhealthy 51 of 365 days1989: Very Unhealthy 36 of 365 days1990: Good 126 of 365 days1990: Moderate 100 of 365 days1990: Unhealthy for Sensitive Groups 76 of 365 days1990: Unhealthy 49 of 365 days1990: Very Unhealthy 14 of 365 days19901991: Good 85 of 365 days1991: Moderate 120 of 365 days1991: Unhealthy for Sensitive Groups 71 of 365 days1991: Unhealthy 60 of 365 days1991: Very Unhealthy 29 of 365 days1992: Good 148 of 366 days1992: Moderate 96 of 366 days1992: Unhealthy for Sensitive Groups 70 of 366 days1992: Unhealthy 40 of 366 days1992: Very Unhealthy 12 of 366 days1993: Good 146 of 365 days1993: Moderate 127 of 365 days1993: Unhealthy for Sensitive Groups 48 of 365 days1993: Unhealthy 37 of 365 days1993: Very Unhealthy 7 of 365 days1994: Good 134 of 365 days1994: Moderate 102 of 365 days1994: Unhealthy for Sensitive Groups 69 of 365 days1994: Unhealthy 44 of 365 days1994: Very Unhealthy 16 of 365 days1995: Good 134 of 365 days1995: Moderate 103 of 365 days1995: Unhealthy for Sensitive Groups 63 of 365 days1995: Unhealthy 43 of 365 days1995: Very Unhealthy 22 of 365 days19951996: Good 134 of 366 days1996: Moderate 104 of 366 days1996: Unhealthy for Sensitive Groups 66 of 366 days1996: Unhealthy 45 of 366 days1996: Very Unhealthy 17 of 366 days1997: Good 134 of 365 days1997: Moderate 115 of 365 days1997: Unhealthy for Sensitive Groups 74 of 365 days1997: Unhealthy 39 of 365 days1997: Very Unhealthy 3 of 365 days1998: Good 187 of 365 days1998: Moderate 102 of 365 days1998: Unhealthy for Sensitive Groups 47 of 365 days1998: Unhealthy 25 of 365 days1998: Very Unhealthy 4 of 365 days1999: Good 120 of 365 days1999: Moderate 162 of 365 days1999: Unhealthy for Sensitive Groups 62 of 365 days1999: Unhealthy 19 of 365 days1999: Very Unhealthy 2 of 365 days2000: Good 140 of 366 days2000: Moderate 142 of 366 days2000: Unhealthy for Sensitive Groups 58 of 366 days2000: Unhealthy 25 of 366 days2000: Very Unhealthy 1 of 366 days20002001: Good 138 of 365 days2001: Moderate 143 of 365 days2001: Unhealthy for Sensitive Groups 61 of 365 days2001: Unhealthy 21 of 365 days2001: Very Unhealthy 2 of 365 days2002: Good 136 of 365 days2002: Moderate 163 of 365 days2002: Unhealthy for Sensitive Groups 53 of 365 days2002: Unhealthy 11 of 365 days2002: Very Unhealthy 2 of 365 days2003: Good 154 of 365 days2003: Moderate 115 of 365 days2003: Unhealthy for Sensitive Groups 68 of 365 days2003: Unhealthy 27 of 365 days2003: Very Unhealthy 1 of 365 days2004: Good 145 of 366 days2004: Moderate 141 of 366 days2004: Unhealthy for Sensitive Groups 66 of 366 days2004: Unhealthy 14 of 366 days2005: Good 173 of 365 days2005: Moderate 130 of 365 days2005: Unhealthy for Sensitive Groups 55 of 365 days2005: Unhealthy 7 of 365 days20052006: Good 188 of 365 days2006: Moderate 125 of 365 days2006: Unhealthy for Sensitive Groups 38 of 365 days2006: Unhealthy 14 of 365 days2007: Good 170 of 365 days2007: Moderate 152 of 365 days2007: Unhealthy for Sensitive Groups 37 of 365 days2007: Unhealthy 6 of 365 days2008: Good 179 of 366 days2008: Moderate 130 of 366 days2008: Unhealthy for Sensitive Groups 50 of 366 days2008: Unhealthy 7 of 366 days2009: Good 181 of 365 days2009: Moderate 144 of 365 days2009: Unhealthy for Sensitive Groups 34 of 365 days2009: Unhealthy 6 of 365 days2010: Good 202 of 365 days2010: Moderate 145 of 365 days2010: Unhealthy for Sensitive Groups 14 of 365 days2010: Unhealthy 4 of 365 days20102011: Good 208 of 365 days2011: Moderate 141 of 365 days2011: Unhealthy for Sensitive Groups 14 of 365 days2011: Unhealthy 2 of 365 days2012: Good 116 of 366 days2012: Moderate 218 of 366 days2012: Unhealthy for Sensitive Groups 31 of 366 days2012: Unhealthy 1 of 366 days2013: Good 116 of 365 days2013: Moderate 238 of 365 days2013: Unhealthy for Sensitive Groups 10 of 365 days2013: Unhealthy 1 of 365 days2014: Good 101 of 365 days2014: Moderate 249 of 365 days2014: Unhealthy for Sensitive Groups 15 of 365 days2015: Good 119 of 365 days2015: Moderate 233 of 365 days2015: Unhealthy for Sensitive Groups 13 of 365 days20152016: Good 120 of 366 days2016: Moderate 237 of 366 days2016: Unhealthy for Sensitive Groups 9 of 366 days2017: Good 117 of 365 days2017: Moderate 215 of 365 days2017: Unhealthy for Sensitive Groups 20 of 365 days2017: Unhealthy 6 of 365 days2017: Very Unhealthy 5 of 365 days2017: Hazardous 2 of 365 days2018: Good 94 of 365 days2018: Moderate 254 of 365 days2018: Unhealthy for Sensitive Groups 16 of 365 days2018: Unhealthy 1 of 365 days2019: Good 175 of 365 days2019: Moderate 181 of 365 days2019: Unhealthy for Sensitive Groups 9 of 365 days2020: Good 185 of 366 days2020: Moderate 155 of 366 days2020: Unhealthy for Sensitive Groups 21 of 366 days2020: Unhealthy 5 of 366 days20202021: Good 157 of 365 days2021: Moderate 198 of 365 days2021: Unhealthy for Sensitive Groups 10 of 365 days2022: Good 171 of 365 days2022: Moderate 183 of 365 days2022: Unhealthy for Sensitive Groups 11 of 365 days2023: Good 220 of 365 days2023: Moderate 133 of 365 days2023: Unhealthy for Sensitive Groups 12 of 365 days2024: Good 191 of 366 days2024: Moderate 160 of 366 days2024: Unhealthy for Sensitive Groups 14 of 366 days2024: Unhealthy 1 of 366 days2025: Good 190 of 365 days2025: Moderate 167 of 365 days2025: Unhealthy for Sensitive Groups 8 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 year0501001502002501980: 90th percentile AQI 2061981: 90th percentile AQI 1951982: 90th percentile AQI 2081983: 90th percentile AQI 2031984: 90th percentile AQI 2021985: 90th percentile AQI 2001986: 90th percentile AQI 2061987: 90th percentile AQI 1901988: 90th percentile AQI 2031989: 90th percentile AQI 2001990: 90th percentile AQI 1691991: 90th percentile AQI 1921992: 90th percentile AQI 1641993: 90th percentile AQI 1541994: 90th percentile AQI 1721995: 90th percentile AQI 1791996: 90th percentile AQI 1791997: 90th percentile AQI 1541998: 90th percentile AQI 1401999: 90th percentile AQI 1332000: 90th percentile AQI 1432001: 90th percentile AQI 1372002: 90th percentile AQI 1192003: 90th percentile AQI 1432004: 90th percentile AQI 1292005: 90th percentile AQI 1192006: 90th percentile AQI 1192007: 90th percentile AQI 1052008: 90th percentile AQI 1152009: 90th percentile AQI 1052010: 90th percentile AQI 872011: 90th percentile AQI 842012: 90th percentile AQI 972013: 90th percentile AQI 772014: 90th percentile AQI 872015: 90th percentile AQI 852016: 90th percentile AQI 842017: 90th percentile AQI 1002018: 90th percentile AQI 882019: 90th percentile AQI 772020: 90th percentile AQI 902021: 90th percentile AQI 802022: 90th percentile AQI 802023: 90th percentile AQI 802024: 90th percentile AQI 842025: 90th percentile AQI 671980: Median AQI 891981: Median AQI 841982: Median AQI 931983: Median AQI 711984: Median AQI 871985: Median AQI 871986: Median AQI 1011987: Median AQI 871988: Median AQI 931989: Median AQI 841990: Median AQI 741991: Median AQI 891992: Median AQI 671993: Median AQI 641994: Median AQI 711995: Median AQI 671996: Median AQI 671997: Median AQI 711998: Median AQI 501999: Median AQI 642000: Median AQI 612001: Median AQI 632002: Median AQI 612003: Median AQI 572004: Median AQI 582005: Median AQI 542006: Median AQI 502007: Median AQI 542008: Median AQI 532009: Median AQI 512010: Median AQI 482011: Median AQI 482012: Median AQI 582013: Median AQI 552014: Median AQI 582015: Median AQI 562016: Median AQI 562017: Median AQI 572018: Median AQI 572019: Median AQI 512020: Median AQI 502021: Median AQI 532022: Median AQI 522023: Median AQI 462024: Median AQI 502025: Median AQI 501980198519901995200020052010201520202025
  • 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
Ozone20255%
Fine particles (PM2.5)15743%
Coarse particles (PM10)62%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536519016780005067131Ozone
2024366191160141005084176Ozone
2023365220133120004680136Ozone
2022365171183110005280140Ozone
2021365157198100005380122Ozone
2020366185155215005090174Ozone
201936517518190005177126Ozone
201836594254161005788166PM2.5
20173651172152065257100961PM2.5
201636612023790005684147PM2.5
2015365119233130005685126PM2.5
2014365101249150005887150PM2.5
2013365116238101005577159PM2.5
2012366116218311005897154Ozone
2011365208141142004884151Ozone
2010365202145144004887161Ozone
20093651811443460051105174Ozone
20083661791305070053115174Ozone
20073651701523760054105190Ozone
200636518812538140050119197Ozone
20053651731305570054119187Ozone
200436614514166140058129182Ozone
200336515411568271057143209Ozone
200236513616353112061119204Ozone
200136513814361212063137208Ozone
200036614014258251061143203Ozone
199936512016262192064133207Ozone
199836518710247254050140248Ozone
199736513411574393071154209Ozone
1996366134104664517067179223Ozone
1995365134103634322067179241Ozone
1994365134102694416071172228Ozone
199336514612748377064154225Ozone
199236614896704012067164219Ozone
199136585120716029089192237Ozone
1990365126100764914074169240Ozone
1989365101107705136084200264Ozone
198836688102696542093203239Ozone
198736511689785626087190251Ozone
1986365791037461480101206242Ozone
198536511791675832087200242Ozone
1984366102107526441087202256Ozone
198336513773604847071203263Ozone
19823659199616054093208266Ozone
198136211296457435084195268Ozone
198036593111505853089206258Ozone

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