EnviroNearby

Lancaster County, Nebraska air quality history

Daily Air Quality Index summaries from EPA monitors in Lancaster, Nebraska, 1980–2025.

85%
Good days in 2025
37
Median daily AQI, 2025
0
Days above 100 in 2025
281
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Lancaster, Nebraska on 281 days. 240 of those days (85%) were in the Good range, and the median daily AQI was 37. That median is higher than the typical monitored county in Nebraska (median 34 across 10 counties), and lower 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 held roughly steady: an average of 80% in 1980–1982 versus 80% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (281 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.

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 248 of 363 days1980: Moderate 110 of 363 days1980: Unhealthy for Sensitive Groups 5 of 363 days19801981: Good 305 of 365 days1981: Moderate 45 of 365 days1981: Unhealthy for Sensitive Groups 7 of 365 days1981: Unhealthy 3 of 365 days1981: Very Unhealthy 5 of 365 days1982: Good 322 of 365 days1982: Moderate 39 of 365 days1982: Unhealthy for Sensitive Groups 3 of 365 days1982: Unhealthy 1 of 365 days1983: Good 327 of 365 days1983: Moderate 36 of 365 days1983: Unhealthy for Sensitive Groups 2 of 365 days1984: Good 348 of 366 days1984: Moderate 18 of 366 days1985: Good 350 of 356 days1985: Moderate 6 of 356 days19851986: Good 262 of 361 days1986: Moderate 96 of 361 days1986: Unhealthy for Sensitive Groups 3 of 361 days1987: Good 339 of 365 days1987: Moderate 26 of 365 days1988: Good 277 of 366 days1988: Moderate 86 of 366 days1988: Unhealthy for Sensitive Groups 3 of 366 days1989: Good 323 of 365 days1989: Moderate 42 of 365 days1990: Good 325 of 365 days1990: Moderate 38 of 365 days1990: Unhealthy for Sensitive Groups 2 of 365 days19901991: Good 327 of 365 days1991: Moderate 38 of 365 days1992: Good 337 of 366 days1992: Moderate 29 of 366 days1993: Good 355 of 365 days1993: Moderate 10 of 365 days1994: Good 342 of 365 days1994: Moderate 22 of 365 days1994: Unhealthy for Sensitive Groups 1 of 365 days1995: Good 339 of 365 days1995: Moderate 26 of 365 days19951996: Good 359 of 366 days1996: Moderate 7 of 366 days1997: Good 351 of 365 days1997: Moderate 14 of 365 days1998: Good 344 of 358 days1998: Moderate 14 of 358 days1999: Good 296 of 364 days1999: Moderate 67 of 364 days1999: Unhealthy 1 of 364 days2000: Good 307 of 366 days2000: Moderate 59 of 366 days20002001: Good 307 of 365 days2001: Moderate 58 of 365 days2002: Good 311 of 365 days2002: Moderate 54 of 365 days2003: Good 307 of 365 days2003: Moderate 57 of 365 days2003: Unhealthy for Sensitive Groups 1 of 365 days2004: Good 322 of 366 days2004: Moderate 43 of 366 days2004: Unhealthy for Sensitive Groups 1 of 366 days2005: Good 309 of 363 days2005: Moderate 53 of 363 days2005: Unhealthy for Sensitive Groups 1 of 363 days20052006: Good 326 of 365 days2006: Moderate 39 of 365 days2007: Good 322 of 362 days2007: Moderate 40 of 362 days2008: Good 324 of 366 days2008: Moderate 42 of 366 days2009: Good 325 of 365 days2009: Moderate 38 of 365 days2009: Unhealthy 1 of 365 days2009: Very Unhealthy 1 of 365 days2010: Good 317 of 359 days2010: Moderate 41 of 359 days2010: Unhealthy for Sensitive Groups 1 of 359 days20102011: Good 320 of 365 days2011: Moderate 45 of 365 days2012: Good 225 of 286 days2012: Moderate 61 of 286 days2013: Good 219 of 257 days2013: Moderate 38 of 257 days2014: Good 220 of 265 days2014: Moderate 44 of 265 days2014: Unhealthy for Sensitive Groups 1 of 265 days2015: Good 220 of 261 days2015: Moderate 41 of 261 days20152016: Good 231 of 261 days2016: Moderate 30 of 261 days2017: Good 235 of 270 days2017: Moderate 35 of 270 days2018: Good 239 of 289 days2018: Moderate 50 of 289 days2019: Good 249 of 288 days2019: Moderate 39 of 288 days2020: Good 261 of 282 days2020: Moderate 21 of 282 days20202021: Good 246 of 276 days2021: Moderate 30 of 276 days2022: Good 258 of 277 days2022: Moderate 19 of 277 days2023: Good 197 of 283 days2023: Moderate 83 of 283 days2023: Unhealthy for Sensitive Groups 2 of 283 days2023: Unhealthy 1 of 283 days2024: Good 237 of 283 days2024: Moderate 46 of 283 days2025: Good 240 of 281 days2025: Moderate 41 of 281 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 year0501001980: 90th percentile AQI 731981: 90th percentile AQI 641982: 90th percentile AQI 531983: 90th percentile AQI 511984: 90th percentile AQI 421985: 90th percentile AQI 401986: 90th percentile AQI 661987: 90th percentile AQI 451988: 90th percentile AQI 671989: 90th percentile AQI 511990: 90th percentile AQI 521991: 90th percentile AQI 511992: 90th percentile AQI 501993: 90th percentile AQI 401994: 90th percentile AQI 471995: 90th percentile AQI 461996: 90th percentile AQI 421997: 90th percentile AQI 441998: 90th percentile AQI 421999: 90th percentile AQI 592000: 90th percentile AQI 582001: 90th percentile AQI 552002: 90th percentile AQI 552003: 90th percentile AQI 562004: 90th percentile AQI 532005: 90th percentile AQI 552006: 90th percentile AQI 512007: 90th percentile AQI 522008: 90th percentile AQI 522009: 90th percentile AQI 522010: 90th percentile AQI 522011: 90th percentile AQI 522012: 90th percentile AQI 572013: 90th percentile AQI 572014: 90th percentile AQI 572015: 90th percentile AQI 522016: 90th percentile AQI 512017: 90th percentile AQI 542018: 90th percentile AQI 552019: 90th percentile AQI 522020: 90th percentile AQI 482021: 90th percentile AQI 532022: 90th percentile AQI 472023: 90th percentile AQI 642024: 90th percentile AQI 542025: 90th percentile AQI 541980: Median AQI 441981: Median AQI 321982: Median AQI 331983: Median AQI 331984: Median AQI 241985: Median AQI 161986: Median AQI 401987: Median AQI 281988: Median AQI 391989: Median AQI 361990: Median AQI 361991: Median AQI 331992: Median AQI 311993: Median AQI 291994: Median AQI 311995: Median AQI 311996: Median AQI 291997: Median AQI 291998: Median AQI 291999: Median AQI 322000: Median AQI 332001: Median AQI 312002: Median AQI 322003: Median AQI 332004: Median AQI 312005: Median AQI 322006: Median AQI 292007: Median AQI 312008: Median AQI 292009: Median AQI 292010: Median AQI 302011: Median AQI 302012: Median AQI 412013: Median AQI 382014: Median AQI 392015: Median AQI 402016: Median AQI 372017: Median AQI 372018: Median AQI 362019: Median AQI 362020: Median AQI 352021: Median AQI 372022: Median AQI 372023: Median AQI 422024: Median AQI 412025: Median AQI 371980198519901995200020052010201520202025
  • 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
Ozone20272%
Fine particles (PM2.5)7928%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025281240410000375487Ozone
2024283237460000415482Ozone
20232831978321004264160Ozone
2022277258190000374764Ozone
2021276246300000375384Ozone
2020282261210000354877Ozone
2019288249390000365270Ozone
2018289239500000365580Ozone
2017270235350000375497Ozone
2016261231300000375174Ozone
2015261220410000405280Ozone
20142652204410003957109Ozone
2013257219380000385777Ozone
2012286225610000415782Ozone
2011365320450000305288Ozone
20103593174110003052108Ozone
20093653253801102952228Ozone
2008366324420000295283Ozone
2007362322400000315295Ozone
2006365326390000295187Ozone
20053633095310003255101Ozone
20043663224310003153103Ozone
20033653075710003356117Ozone
2002365311540000325585Ozone
2001365307580000315593Ozone
2000366307590000335894Ozone
19993642966701003259174Ozone
1998358344140000294279Ozone
19973653511400002944100Ozone
199636635970000294263Ozone
1995365339260000314690Ozone
19943653422210003147101Ozone
1993365355100000294058CO
19923663372900003150100Ozone
19913653273800003351100Ozone
19903653253820003652116CO
1989365323420000365194CO
19883662778630003967112CO
1987365339260000284595CO
19863612629630004066130CO
198535635060000164064CO
1984366348180000244284CO
19833653273620003351130Ozone
19823653223931003353153Ozone
19813653054573503264267CO
198036324811050004473118CO

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 Nebraska with a similar median AQI in 2025

All monitored counties in Nebraska

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