Colorado · County air quality · 2025

Clear Creek County, Colorado

Median AQI 48 (Good). 67.9% of monitored days rated Good, direct from EPA Air Quality System stations.

48
Median AQI
67.9%
Good-air days
0
Unhealthy days
28%
Cleaner than US counties

Clear Creek County's 2025 annual median AQI is 48 (Good), with 67.9% Good days

According to the U.S. EPA Air Quality System, Clear Creek County, Colorado posted a 2025 median AQI of 48 (Good) across 315 monitored days, with 67.9% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US
Clear Creek County's 67.9% Good-day share places it cleaner than 28% of US counties in 2025.
Closest median-AQI peer
Adair County (55.8% Good, median AQI 48) is the closest nationwide median-AQI peer to Clear Creek County.
2020–2025 trend
Clear Creek County's floor-qualifying Good-day share is improving from 2020 to 2025 (58.6% → 67.9%).
Median AQI
Median AQI: 48

According to the 2025 EPA AQS county release on PlainAirData, Clear Creek County, Colorado ranks #843 of 951 by median AQI (48) and #687 by good-day share (67.9%). Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ largest of 7 at 100.0% Good days #1 by good-day share (100.0%, median AQI 9) at median-AQI #7.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Clear Creek County's Good-day share rose from 57.5% to 67.9% between the 2024 and 2025 EPA annual releases, a change of +10.4 percentage points.
  • Clear Creek County's peak single-day AQI fell from 136 to 100 between the 2024 and 2025 EPA annual releases, a change of -36 points.

Compared against 351 monitored days in 2024 and 315 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Data updated August 2026

Clear Creek County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 315 monitored days G M Median AQI 48 0 50 100 150 200 300 500 Clear Creek County
  • Good · 214 d · 67.9%
  • Moderate · 101 d · 32.1%

How did Clear Creek County's air break down in 2025?

Across 315 monitored days, 214 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 100 (Moderate).

EPA AQS →
Clear Creek County, Good days share 67.9%
National avg

Share of monitored days at AQI 0-50 (Good band).

Clear Creek 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).

Where Clear Creek County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Clear Creek County's Good-day share is 67.9% - cleaner than 28% of that comparison set.

Clear Creek County Good-day share vs. every US county

Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

67.9% 28th percentile higher than 28% of 951 US counties

0.0%–5.0%: 0 US counties (0%). Below this entry. 5.0%–10.0%: 1 US counties (0%). Below this entry. 10.0%–15.0%: 4 US counties (0%). Below this entry. 15.0%–20.0%: 4 US counties (0%). Below this entry. 20.0%–25.0%: 1 US counties (0%). Below this entry. 25.0%–30.0%: 5 US counties (1%). Below this entry. 30.0%–35.0%: 9 US counties (1%). Below this entry. 35.0%–40.0%: 4 US counties (0%). Below this entry. 40.0%–45.0%: 16 US counties (2%). Below this entry. 45.0%–50.0%: 16 US counties (2%). Below this entry. 50.0%–55.0%: 32 US counties (3%). Below this entry. 55.0%–60.0%: 50 US counties (5%). Below this entry. 60.0%–65.0%: 77 US counties (8%). Below this entry. 65.0%–70.0%: 93 US counties (10%). This entry sits in this band. 70.0%–75.0%: 109 US counties (11%). Above this entry. 75.0%–80.0%: 114 US counties (12%). Above this entry. 80.0%–85.0%: 123 US counties (13%). Above this entry. 85.0%–90.0%: 99 US counties (10%). Above this entry. 90.0%–95.0%: 117 US counties (12%). Above this entry. 95.0%–100.0%: 70 US counties (7%). Above this entry. 100.0%–105.0%: 7 US counties (1%). Above this entry. This county 0.0% 100% every floor-qualified US county, bucketed by value

Each bar is a band; taller bars hold more US counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Clear Creek County.

Clear Creek County, Colorado criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. Ozone · 100.0% 0% 25% 50% 75% 100% Clear Creek County, Colorado · 315 monitored days Criteria pollutant column
  • Ozone · 315 days · 100.0%

2024 daily-monitor rhythm in Clear Creek County

Month-by-month median AQI from EPA day-level county monitors (351 reported days in 2024). Jul posted the highest typical readings (median AQI 80, peak 136); Jan was cleanest at median 42. Summer months (Jun–Aug) averaged median AQI 64 vs 44 in Dec–Feb.

0 20 40 60 80 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 42 47 48 61 71 61 80 50 58 46 46 44
Clear Creek County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,665 daily readings show a recurring local pattern: Jul has the highest matched-month median AQI (73), while Jan is lowest (44). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 4340--4464618054464646
2021 454548516160937463444344
2022 454746515064586149424443
2023 434749586776716149444544
2024 424748617161805058464644

Lower AQI is better. The colors summarize EPA AQI bands; gaps mean the county had no day-level record for that month.

Health Impact Assessment

Moderate

Clear Creek County's air quality is rated Moderate based on 67.9% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 67.9% of monitored days in 2025, with a median AQI of 48. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is Ozone, driving AQI on 315 of 315 monitored days.

5-Year Air Quality Trend

Air quality is improving in Clear Creek County. Highest Good-day share: 2022 (68.0%, 244 of 359 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 140 87 10 2 49
2021 206 127 22 2 49
2022 244 110 5 0 47
2023 204 147 8 0 49
2024 202 139 10 0 49
2025 214 101 0 0 48

How does Clear Creek County compare?

How Clear Creek County compares

Good-day share worse than typical
Clear Creek County 67.9%
Adair County, Oklahoma 55.8%
Typical US county 76.0%
Median AQI worse than typical
Clear Creek County 48
Adair County, Oklahoma 48
Typical US county 39
Unhealthy days / yr better than typical
Clear Creek County 0
Adair County, Oklahoma 2
Typical US county 1

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. Spotted a figure that looks wrong? Report a correction.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Clear Creek County, Colorado · 2020–2025

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Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.

Every figure on PlainAirData 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.