Median AQI
24
Good
Colorado · County air quality · 2025
Prowers County, Colorado
Median AQI 24 (Good). 91.5% of monitored days rated Good, direct from EPA Air Quality System stations.
- 24
- Median AQI
- 91.5%
- Good-air days
- 2
- Unhealthy days
- 79%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Prowers County's air is good on balance, cleaner than most US counties, a median AQI of 24 with 91.5% of 211 monitored days in the Good band, driven mainly by PM2.5.
- 24
- median AQI · Good
- 91.5%
- days rated Good
- PM2.5
- main pollutant
- 79%
- cleaner than US counties
2 days reached Unhealthy or worse; the worst single reading hit AQI 652 - a reading beyond the EPA’s standard 0–500 AQI scale, reflecting an extreme wildfire-smoke event or a transient monitor anomaly.
Data updated July 2026
- Good · 193 d · 91.5%
- Moderate · 16 d · 7.6%
- Very Unhealthy · 1 d · 0.5%
- Hazardous · 1 d · 0.5%
How did Prowers County's air break down in 2025?
Across 211 monitored days, 193 fell in the Good band (AQI 0–50) and 2 reached Unhealthy or worse. The worst single day peaked at AQI 652 (Hazardous) - a reading beyond the EPA’s standard 0–500 AQI scale, reflecting an extreme wildfire-smoke event or a transient monitor anomaly.
EPA AQS →Air quality data from EPA Air Quality System (2025). 211 days monitored. Median AQI: 24 (Good).
Insights: Prowers County, Colorado. EPA monitors recorded a median Air Quality Index of 24 across 211 measured days in 2025, earning a Good classification and a Excellent health grade. Of those days, 193 (91%) fell in the Good band (AQI 0–50), 16 (8%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 46, while the worst single-day peak hit 652 (Hazardous). Residents averaged about 27.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (176 days), PM10 (35 days). Across the 2020–2025 trend window, good days shifted by -134 and the median AQI moved +7 points, placing the multi-year trajectory at worsening. Residents and visitors experienced 2 unhealthy-or-worse days combined, periods when the EPA recommends sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Adams (50.2% good, AQI 50); Alamosa (90.8% good, AQI 24); Arapahoe (47.3% good, AQI 51); Archuleta (79.5% good, AQI 32); Boulder (50.9% good, AQI 50); Clear Creek (64.4% good, AQI 48).
Air Quality Summary
Good Days
91.5%
193 of 211 monitored days
16.5pp vs 75% target
Max AQI Recorded
652
Hazardous
Health Grade
Excellent
90th-pct AQI 46
Prowers County, Good days share 91.5%
National avg
Share of monitored days at AQI 0-50 (Good band).
Prowers County, Unhealthy-or-worse share 0.9%
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 211 monitored days across EPA AQI categories.
Good
193
91%
Moderate
16
8%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
1
0%
Hazardous
1
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Prowers County.
- PM2.5 · 176 days · 83.4%
- PM10 · 35 days · 16.6%
Health Impact Assessment
Excellent
Prowers County's air quality is rated Excellent based on 91.5% good air days. There were 2 unhealthy days in 2025 when outdoor activity should be limited.
Air quality posed significant health risk in 2025. Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, pregnant women, and adults over 65, should monitor AirNow.gov alerts and limit outdoor activity on Unhealthy (AQI 151+) and Very Unhealthy (201+) days. Peak readings reached AQI 652, beyond EPA's standard 0-500 scale, indicating an extreme event.
Sensitive group advisory
People with asthma, COPD, heart disease, children, pregnant women, and adults 65+ should follow EPA AQI alerts daily and limit outdoor exertion when AQI exceeds 100. Real-time conditions: airnow.gov.
Note: EPA's standard AQI scale caps at 500 (Hazardous category 301-500). The 652 peak reading represents an extreme event, typically wildfire smoke, extrapolated beyond the index's design range. See EPA wildfire smoke guidance.
The dominant pollutant is PM2.5, driving AQI on 176 of 211 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Prowers County. Best year: 2021 (345 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 327 | 19 | 1 | 2 | 17 | 238 |
| 2021 | 345 | 14 | 1 | 0 | 19 | 584 |
| 2022 | 330 | 22 | 0 | 1 | 18 | 330 |
| 2023 | 336 | 13 | 1 | 0 | 19 | 103 |
| 2024 | 321 | 45 | 0 | 0 | 25 | 98 |
| 2025 | 193 | 16 | 0 | 0 | 24 | 652 |
How does Prowers County compare?
How Prowers County compares
Good-day share better than US avg
Prowers County 91.5%
Adams County, Colorado 50.2%
US average 76.5%
Median AQI better than US avg
Prowers County 24
Adams County, Colorado 50
US average 38
Unhealthy days / yr worse than US avg
Prowers County 2
Adams County, Colorado 0
US average 0
Other Counties in Colorado
Air quality comparison for nearby counties in Colorado.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Prowers County.
Alamosa County, Colorado
AQI 24 · 90.8% good
Anchorage County, Alaska
AQI 24 · 80.8% good
Charlton County, Georgia
AQI 24 · 79.0% good
Crook County, Oregon
AQI 24 · 80.7% good
Culberson County, Texas
AQI 24 · 80.0% good
Kootenai County, Idaho
AQI 24 · 88.4% good
What Prowers County's air means for you
On most days the air here is fine, but PM2.5 drives 2 unhealthy-or-worse days a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 24 means for exposure. Health guidance
- See how Prowers County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Prowers County with its Colorado neighbours before drawing a conclusion about the region. All of Colorado
Based on 211 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 Prowers County, Colorado? ▼
Prowers County has a median Air Quality Index (AQI) of 24, rated "Good." 91.5% of monitored days (193 out of 211) had good air quality in 2025.
What is the main pollutant in Prowers County? ▼
The primary pollutant in Prowers County is Fine Particles (PM2.5), which was the main AQI driver on 176 days (83% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Prowers County have? ▼
In 2025, Prowers County recorded 2 unhealthy air days (0 Unhealthy, 1 Very Unhealthy, 1 Hazardous). The maximum AQI reached 652 - a reading beyond the EPA’s standard 0–500 AQI scale, reflecting an extreme wildfire-smoke event or a transient monitor anomaly.
Is the air quality in Prowers County getting better or worse? ▼
Air quality in Prowers County is worsening based on 5-year trends (2020-2025). Best year: 2021 with 345 good days. Worst year: 2025 with 193 good days.
What does AQI 24 mean for health? ▼
Prowers County's median AQI of 24 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 Prowers County compare to other counties in Colorado? ▼
Prowers County has 91.5% good air days. Nearby counties in Colorado: Adams (50.2% good), Alamosa (90.8% good), Arapahoe (47.3% good), Archuleta (79.5% good), Boulder (50.9% good), Clear Creek (64.4% good).
What is the 90th percentile AQI in Prowers County? ▼
The 90th percentile AQI for Prowers County is 46, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 652 - a reading beyond the EPA’s standard 0–500 AQI scale, reflecting an extreme wildfire-smoke event or a transient monitor anomaly (Hazardous).
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.