Median AQI
22
Good
Kansas · County air quality · 2025
Chase County, Kansas
Median AQI 22 (Good). 88.9% of monitored days rated Good, direct from EPA Air Quality System stations.
- 22
- Median AQI
- 88.9%
- Good-air days
- 0
- Unhealthy days
- 73%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Chase County's air is good on balance, cleaner than the median US county, a median AQI of 22 with 88.9% of 18 monitored days in the Good band, driven mainly by PM2.5.
- 22
- median AQI · Good
- 88.9%
- days rated Good
- PM2.5
- main pollutant
- 73%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 56.
Data updated July 2026
- Good · 16 d · 88.9%
- Moderate · 2 d · 11.1%
How did Chase County's air break down in 2025?
Across 18 monitored days, 16 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 56 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 18 days monitored. Median AQI: 22 (Good).
Insights: Chase County, Kansas. EPA monitors recorded a median Air Quality Index of 22 across 18 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 16 (89%) fell in the Good band (AQI 0–50), 2 (11%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 53, while the worst single-day peak hit 56 (Moderate). Residents averaged about 26.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (18 days). Across the 2020–2025 trend window, good days shifted by -94 and the median AQI moved -2 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 56, moderate but never Unhealthy. Nearby counties show comparable readings: Douglas (90.7% good, AQI 41); Ford (89.4% good, AQI 26); Johnson (71.8% good, AQI 43); Leavenworth (93.9% good, AQI 36); Neosho (73.5% good, AQI 43); Sedgwick (58.6% good, AQI 48).
Air Quality Summary
Good Days
88.9%
16 of 18 monitored days
13.9pp vs 75% target
Max AQI Recorded
56
Moderate
Health Grade
Good
90th-pct AQI 53
Chase County, Good days share 88.9%
National avg
Share of monitored days at AQI 0-50 (Good band).
Chase County, Unhealthy-or-worse share 0.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 18 monitored days across EPA AQI categories.
Good
16
89%
Moderate
2
11%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Chase County.
- PM2.5 · 18 days · 100.0%
Health Impact Assessment
Good
Chase County's air quality is rated Good based on 88.9% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 88.9% of monitored days in 2025, with a median AQI of 22. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 18 of 18 monitored days.
5-Year Air Quality Trend
Air quality is stable in Chase County. Best year: 2022 (110 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 110 | 11 | 0 | 0 | 24 | 63 |
| 2021 | 102 | 18 | 0 | 0 | 27 | 99 |
| 2022 | 110 | 11 | 0 | 0 | 25 | 66 |
| 2023 | 98 | 19 | 0 | 0 | 29 | 79 |
| 2024 | 106 | 16 | 0 | 0 | 29 | 94 |
| 2025 | 16 | 2 | 0 | 0 | 22 | 56 |
How does Chase County compare?
How Chase County compares
Good-day share better than US avg
Chase County 88.9%
Douglas County, Kansas 90.7%
US average 76.5%
Median AQI better than US avg
Chase County 22
Douglas County, Kansas 41
US average 38
Unhealthy days / yr about average
Chase County 0
Douglas County, Kansas 0
US average 0
Other Counties in Kansas
Air quality comparison for nearby counties in Kansas.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Chase County.
Blaine County, Idaho
AQI 22 · 99.4% good
Cass County, Minnesota
AQI 22 · 94.4% good
Deschutes County, Oregon
AQI 22 · 93.4% good
Douglas County, Nevada
AQI 22 · 90.9% good
Franklin County, Idaho
AQI 22 · 95.8% good
Franklin County, Washington
AQI 22 · 93.7% good
What Chase County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 22 means for exposure. Health guidance
- See how Chase County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Chase County with its Kansas neighbours before drawing a conclusion about the region. All of Kansas
Based on 18 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Chase County, Kansas? ▼
Chase County has a median Air Quality Index (AQI) of 22, rated "Good." 88.9% of monitored days (16 out of 18) had good air quality in 2025.
What is the main pollutant in Chase County? ▼
The primary pollutant in Chase County is Fine Particles (PM2.5), which was the main AQI driver on 18 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Chase County have? ▼
In 2025, Chase County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 56.
Is the air quality in Chase County getting better or worse? ▼
Air quality in Chase County is stable based on 5-year trends (2020-2025). Best year: 2022 with 110 good days. Worst year: 2025 with 16 good days.
What does AQI 22 mean for health? ▼
Chase County's median AQI of 22 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Chase County compare to other counties in Kansas? ▼
Chase County has 88.9% good air days. Nearby counties in Kansas: Douglas (90.7% good), Ford (89.4% good), Johnson (71.8% good), Leavenworth (93.9% good), Neosho (73.5% good), Sedgwick (58.6% good).
What is the 90th percentile AQI in Chase County? ▼
The 90th percentile AQI for Chase County is 53, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 56 (Moderate).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer.
Every figure on PlainAir is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.