Median AQI
23
Good
Alaska · County air quality · 2025
Juneau County, Alaska
Median AQI 23 (Good). 84.3% of monitored days rated Good, direct from EPA Air Quality System stations.
- 23
- Median AQI
- 84.3%
- Good-air days
- 0
- Unhealthy days
- 67%
- Cleaner than US counties
Juneau County's 2025 annual median AQI is 23 (Good), with 84.3% Good days
According to the U.S. EPA Air Quality System, Juneau County, Alaska posted a 2025 median AQI of 23 (Good) across 363 monitored days, with 84.3% 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
- Juneau County's 84.3% Good-day share places it cleaner than 67% of US counties in 2025.
- Closest median-AQI peer
- Deschutes County (89.3% Good, median AQI 23) is the closest nationwide median-AQI peer to Juneau County.
- 2020–2025 trend
- Juneau County's floor-qualifying Good-day share is worsening from 2020 to 2025 (88.6% → 84.3%).
- Median AQI
- Median AQI: 23
The verdict
According to EPA Air Quality System monitoring data, Juneau County's air is good on balance, cleaner than the median US county, a median AQI of 23 with 84.3% of 363 monitored days in the Good band, driven mainly by PM2.5.
- 23
- median AQI · Good
- 84.3%
- days rated Good
- PM2.5
- main pollutant
- 67%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 138.
Annual release change
What changed in the 2025 EPA annual release
- Juneau County's peak single-day AQI rose from 84 to 138 between the 2024 and 2025 EPA annual releases, a change of +54 points.
- Juneau County's Good-day share fell from 85.4% to 84.3% between the 2024 and 2025 EPA annual releases, a change of -1.1 percentage points.
Data updated August 2026
- Good · 306 d · 84.3%
- Moderate · 56 d · 15.4%
- USG · 1 d · 0.3%
How did Juneau County's air break down in 2025?
Across 363 monitored days, 306 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 138 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 363 days monitored. Median AQI: 23 (Good).
Insights: Juneau County, Alaska. EPA monitors recorded a median Air Quality Index of 23 across 363 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 306 (84%) fell in the Good band (AQI 0–50), 56 (15%) registered Moderate readings, and 1 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 58, while the worst single-day peak hit 138 (USG). Residents averaged about 25.3 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (363 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -4.3 points and the median AQI moved +4 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 138, usg but never Unhealthy. Nearby counties show comparable readings: Aleutians East (99.0% good, AQI 11); Anchorage (79.2% good, AQI 26); Denali (99.7% good, AQI 33); Fairbanks North Star (56.4% good, AQI 44); Kenai Peninsula (100.0% good, AQI 9); Matanuska-Susitna (91.5% good, AQI 9).
Air Quality Summary
Good Days
84.3%
306 of 363 monitored days
9.3pp vs 75% target
Max AQI Recorded
138
USG
Health Grade
Good
90th-pct AQI 58
Juneau County, Good days share 84.3%
National avg
Share of monitored days at AQI 0-50 (Good band).
Juneau 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 363 monitored days across EPA AQI categories.
Good
306
84%
Moderate
56
15%
USG
1
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 Juneau County.
- PM2.5 · 363 days · 100.0%
Health Impact Assessment
Good
Juneau County's air quality is rated Good based on 84.3% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 84.3% of monitored days in 2025, with a median AQI of 23. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 363 of 363 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Juneau County. Highest Good-day share: 2020 (88.6%, 320 of 361 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 320 | 40 | 1 | 0 | 19 | 101 |
| 2021 | 315 | 42 | 0 | 0 | 20 | 89 |
| 2022 | 291 | 51 | 0 | 0 | 21 | 95 |
| 2023 | 314 | 50 | 0 | 0 | 24 | 78 |
| 2024 | 304 | 52 | 0 | 0 | 24 | 84 |
| 2025 | 306 | 56 | 1 | 0 | 23 | 138 |
How does Juneau County compare?
How Juneau County compares
Good-day share better than typical
Juneau County 84.3%
Deschutes County, Oregon 89.3%
Typical US county 76.0%
Median AQI better than typical
Juneau County 23
Deschutes County, Oregon 23
Typical US county 39
Unhealthy days / yr better than typical
Juneau County 0
Deschutes County, Oregon 1
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Juneau County (23), not geographic neighbors.
Deschutes County, Oregon
Median AQI 23 · 89.3% Good-day share
Franklin County, Washington
Median AQI 23 · 86.7% Good-day share
Fremont County, Colorado
Median AQI 23 · 93.4% Good-day share
Glacier County, Montana
Median AQI 23 · 91.7% Good-day share
Mason County, Washington
Median AQI 23 · 90.4% Good-day share
Scotts Bluff County, Nebraska
Median AQI 23 · 95.8% Good-day share
Same primary pollutant: PM2.5
PM2.5 led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Edgecombe County, North Carolina
84.4% Good-day share · median AQI 38
Oneida County, New York
84.4% Good-day share · median AQI 27
Union County, Oregon
84.4% Good-day share · median AQI 27
Roanoke County, Virginia
83.8% Good-day share · median AQI 37
Montgomery County, Tennessee
83.8% Good-day share · median AQI 32
Silver Bow County, Montana
84.9% Good-day share · median AQI 28
Alaska counties on the map
Geographic containment only, other monitored counties in Alaska, independent of AQI or pollutant match.
What Juneau 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 23 means for exposure. Health guidance
- See how Juneau County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Juneau County with its Alaska neighbours before drawing a conclusion about the region. All of Alaska
Based on 363 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Juneau County, Alaska? ▼
Juneau County has a median Air Quality Index (AQI) of 23, rated "Good." 84.3% of monitored days (306 out of 363) had good air quality in 2025.
What is the main pollutant in Juneau County? ▼
The primary pollutant in Juneau County is Fine Particles (PM2.5), which was the main AQI driver on 363 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Juneau County have? ▼
In 2025, Juneau County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 138.
Is the air quality in Juneau County getting better or worse? ▼
Air quality in Juneau County is worsening across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 88.6% (320 of 361 days). Lowest qualifying Good-day share: 2025 at 84.3% (306 of 363 days).
What does AQI 23 mean for health? ▼
Juneau County's median AQI of 23 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Juneau County compare to other counties in Alaska? ▼
Juneau County has 84.3% good air days. Nearby counties in Alaska: Aleutians East (99.0% good), Anchorage (79.2% good), Denali (99.7% good), Fairbanks North Star (56.4% good), Kenai Peninsula (100.0% good), Matanuska-Susitna (91.5% good).
What is the 90th percentile AQI in Juneau County? ▼
The 90th percentile AQI for Juneau County is 58, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 138 (USG).
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 Juneau County, Alaska · 2020–2025
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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.