Median AQI
25
Good
Kansas · County air quality · 2025
Sherman County, Kansas
Median AQI 25 (Good). 86.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 25
- Median AQI
- 86.6%
- Good-air days
- 0
- Unhealthy days
- 68%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Sherman County's air is good on balance, cleaner than the median US county, a median AQI of 25 with 86.6% of 149 monitored days in the Good band, driven mainly by PM2.5.
- 25
- median AQI · Good
- 86.6%
- days rated Good
- PM2.5
- main pollutant
- 68%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 93.
Data updated July 2026
- Good · 129 d · 86.6%
- Moderate · 20 d · 13.4%
How did Sherman County's air break down in 2025?
Across 149 monitored days, 129 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 93 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 149 days monitored. Median AQI: 25 (Good).
Insights: Sherman County, Kansas. EPA monitors recorded a median Air Quality Index of 25 across 149 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 129 (87%) fell in the Good band (AQI 0–50), 20 (13%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 54, while the worst single-day peak hit 93 (Moderate). Residents averaged about 26.0 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (119 days), PM10 (30 days). Across the 2020–2025 trend window, good days shifted by -153 and the median AQI moved +12 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 93, moderate but never Unhealthy. Nearby counties show comparable readings: Chase (88.9% good, AQI 22); 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).
Air Quality Summary
Good Days
86.6%
129 of 149 monitored days
11.6pp vs 75% target
Max AQI Recorded
93
Moderate
Health Grade
Good
90th-pct AQI 54
Sherman County, Good days share 86.6%
National avg
Share of monitored days at AQI 0-50 (Good band).
Sherman 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 149 monitored days across EPA AQI categories.
Good
129
87%
Moderate
20
13%
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 Sherman County.
- PM2.5 · 119 days · 79.9%
- PM10 · 30 days · 20.1%
Health Impact Assessment
Good
Sherman County's air quality is rated Good based on 86.6% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 86.6% of monitored days in 2025, with a median AQI of 25. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 119 of 149 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Sherman County. Best year: 2022 (338 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 282 | 20 | 1 | 0 | 13 | 106 |
| 2021 | 308 | 11 | 0 | 0 | 17 | 221 |
| 2022 | 338 | 18 | 3 | 0 | 18 | 494 |
| 2023 | 315 | 19 | 0 | 0 | 19 | 78 |
| 2024 | 271 | 51 | 2 | 0 | 27 | 138 |
| 2025 | 129 | 20 | 0 | 0 | 25 | 93 |
How does Sherman County compare?
How Sherman County compares
Good-day share better than US avg
Sherman County 86.6%
Chase County, Kansas 88.9%
US average 76.5%
Median AQI better than US avg
Sherman County 25
Chase County, Kansas 22
US average 38
Unhealthy days / yr about average
Sherman County 0
Chase 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 Sherman County.
Baker County, Oregon
AQI 25 · 89.0% good
Brown County, South Dakota
AQI 25 · 87.1% good
Columbia County, Oregon
AQI 25 · 96.7% good
Fremont County, Colorado
AQI 25 · 91.1% good
Lubbock County, Texas
AQI 25 · 89.9% good
Walla Walla County, Washington
AQI 25 · 86.0% good
What Sherman 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 25 means for exposure. Health guidance
- See how Sherman County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Sherman County with its Kansas neighbours before drawing a conclusion about the region. All of Kansas
Based on 149 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 Sherman County, Kansas? ▼
Sherman County has a median Air Quality Index (AQI) of 25, rated "Good." 86.6% of monitored days (129 out of 149) had good air quality in 2025.
What is the main pollutant in Sherman County? ▼
The primary pollutant in Sherman County is Fine Particles (PM2.5), which was the main AQI driver on 119 days (80% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Sherman County have? ▼
In 2025, Sherman County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 93.
Is the air quality in Sherman County getting better or worse? ▼
Air quality in Sherman County is worsening based on 5-year trends (2020-2025). Best year: 2022 with 338 good days. Worst year: 2025 with 129 good days.
What does AQI 25 mean for health? ▼
Sherman County's median AQI of 25 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 Sherman County compare to other counties in Kansas? ▼
Sherman County has 86.6% good air days. Nearby counties in Kansas: Chase (88.9% good), Douglas (90.7% good), Ford (89.4% good), Johnson (71.8% good), Leavenworth (93.9% good), Neosho (73.5% good).
What is the 90th percentile AQI in Sherman County? ▼
The 90th percentile AQI for Sherman County is 54, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 93 (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.