EnviroNearby

Cedar County, Missouri air quality history

Daily Air Quality Index summaries from EPA monitors in Cedar, Missouri, 1998–2025.

82%
Good days in 2025
39
Median daily AQI, 2025
1
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 Cedar, Missouri on 365 days. 298 of those days (82%) were in the Good range, and the median daily AQI was 39. That median is about the same as the typical monitored county in Missouri (median 41 across 19 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 194 days. Across the years with fuller monitoring, the share of Good days rose: an average of 46% in 1999–2001 versus 79% in 2023–2025.

Years with fewer than 120 monitored days (1998) 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%1998: Good 44 of 92 days1998: Moderate 26 of 92 days1998: Unhealthy for Sensitive Groups 18 of 92 days1998: Unhealthy 4 of 92 days19981999: Good 122 of 260 days1999: Moderate 115 of 260 days1999: Unhealthy for Sensitive Groups 21 of 260 days1999: Unhealthy 2 of 260 days2000: Good 117 of 264 days2000: Moderate 119 of 264 days2000: Unhealthy for Sensitive Groups 21 of 264 days2000: Unhealthy 7 of 264 days20002001: Good 122 of 256 days2001: Moderate 120 of 256 days2001: Unhealthy for Sensitive Groups 14 of 256 days2002: Good 137 of 265 days2002: Moderate 109 of 265 days2002: Unhealthy for Sensitive Groups 17 of 265 days2002: Unhealthy 2 of 265 days20022003: Good 134 of 262 days2003: Moderate 115 of 262 days2003: Unhealthy for Sensitive Groups 13 of 262 days2004: Good 165 of 253 days2004: Moderate 84 of 253 days2004: Unhealthy for Sensitive Groups 3 of 253 days2004: Unhealthy 1 of 253 days20042005: Good 129 of 262 days2005: Moderate 119 of 262 days2005: Unhealthy for Sensitive Groups 14 of 262 days2006: Good 140 of 361 days2006: Moderate 212 of 361 days2006: Unhealthy for Sensitive Groups 9 of 361 days20062007: Good 109 of 361 days2007: Moderate 242 of 361 days2007: Unhealthy for Sensitive Groups 10 of 361 days2008: Good 138 of 352 days2008: Moderate 212 of 352 days2008: Unhealthy for Sensitive Groups 2 of 352 days20082009: Good 207 of 354 days2009: Moderate 147 of 354 days2010: Good 136 of 363 days2010: Moderate 226 of 363 days2010: Unhealthy for Sensitive Groups 1 of 363 days20102011: Good 118 of 342 days2011: Moderate 214 of 342 days2011: Unhealthy for Sensitive Groups 10 of 342 days2012: Good 153 of 344 days2012: Moderate 172 of 344 days2012: Unhealthy for Sensitive Groups 18 of 344 days2012: Unhealthy 1 of 344 days20122013: Good 205 of 351 days2013: Moderate 146 of 351 days2014: Good 229 of 364 days2014: Moderate 134 of 364 days2014: Unhealthy for Sensitive Groups 1 of 364 days20142015: Good 247 of 352 days2015: Moderate 105 of 352 days2016: Good 273 of 354 days2016: Moderate 81 of 354 days20162017: Good 262 of 363 days2017: Moderate 101 of 363 days2018: Good 236 of 363 days2018: Moderate 127 of 363 days20182019: Good 237 of 351 days2019: Moderate 114 of 351 days2020: Good 277 of 352 days2020: Moderate 75 of 352 days20202021: Good 242 of 350 days2021: Moderate 108 of 350 days2022: Good 274 of 349 days2022: Moderate 75 of 349 days20222023: Good 256 of 363 days2023: Moderate 103 of 363 days2023: Unhealthy for Sensitive Groups 4 of 363 days2024: Good 310 of 362 days2024: Moderate 52 of 362 days20242025: Good 298 of 365 days2025: Moderate 66 of 365 days2025: Unhealthy for Sensitive Groups 1 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 year0501001501998: 90th percentile AQI 1191999: 90th percentile AQI 1002000: 90th percentile AQI 1012001: 90th percentile AQI 872002: 90th percentile AQI 932003: 90th percentile AQI 802004: 90th percentile AQI 642005: 90th percentile AQI 902006: 90th percentile AQI 792007: 90th percentile AQI 802008: 90th percentile AQI 702009: 90th percentile AQI 642010: 90th percentile AQI 742011: 90th percentile AQI 812012: 90th percentile AQI 842013: 90th percentile AQI 642014: 90th percentile AQI 632015: 90th percentile AQI 592016: 90th percentile AQI 562017: 90th percentile AQI 562018: 90th percentile AQI 622019: 90th percentile AQI 612020: 90th percentile AQI 552021: 90th percentile AQI 582022: 90th percentile AQI 612023: 90th percentile AQI 672024: 90th percentile AQI 532025: 90th percentile AQI 551998: Median AQI 511999: Median AQI 512000: Median AQI 532001: Median AQI 512002: Median AQI 492003: Median AQI 492004: Median AQI 442005: Median AQI 512006: Median AQI 542007: Median AQI 562008: Median AQI 542009: Median AQI 462010: Median AQI 532011: Median AQI 562012: Median AQI 532013: Median AQI 452014: Median AQI 442015: Median AQI 402016: Median AQI 412017: Median AQI 412018: Median AQI 432019: Median AQI 442020: Median AQI 392021: Median AQI 422022: Median AQI 412023: Median AQI 442024: Median AQI 402025: Median AQI 39199820002002200420062008201020122014201620182020202220242025
  • 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
Fine particles (PM2.5)19453%
Ozone17147%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253652986610003955106PM2.5
2024362310520000405380Ozone
202336325610340004467122Ozone
20223492747500004161100Ozone
20213502421080000425888PM2.5
2020352277750000395599PM2.5
20193512371140000446180PM2.5
20183632361270000436284PM2.5
20173632621010000415684PM2.5
2016354273810000415671PM2.5
20153522471050000405988PM2.5
201436422913410004463101PM2.5
20133512051460000456487PM2.5
2012344153172181005384164PM2.5
2011342118214100005681136PM2.5
201036313622610005374133PM2.5
20093542071470000466490PM2.5
200835213821220005470122PM2.5
2007361109242100005680129PM2.5
200636114021290005479126PM2.5
2005262129119140005190147Ozone
20042531658431004464151Ozone
2003262134115130004980140Ozone
2002265137109172004993159Ozone
2001256122120140005187122Ozone
20002641171192170053101179Ozone
19992601221152120051100172Ozone
19989244261840051119161Ozone

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 Missouri with a similar median AQI in 2025

All monitored counties in Missouri

Source: U.S. EPA AirData, “Annual AQI by County” files for 1998–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem