Metro area air quality · 2025

Aberdeen, SD

Median AQI 27 (Good). 83.6% of monitored days rated Good across this metro's EPA monitoring network.

27
Median AQI
83.6%
Good-air days
0
Unhealthy days
75%
Cleaner than US metros

Aberdeen, SD posted a 2025 median AQI of 27 (Good) with 83.6% Good days

According to the U.S. EPA Air Quality System, the Aberdeen, SD CBSA recorded a median AQI of 27 across 360 monitored days in 2025, with 83.6% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US metros
The Aberdeen, SD CBSA's 83.6% Good-day share places it cleaner than 75% of US metros in 2025.
Closest median-AQI peer
Albany, OR (80.0% Good, median AQI 27) is the closest nationwide median-AQI peer to Aberdeen, SD.
2020–2025 Good-day shift
Aberdeen, SD's Good-day share moved +0.4 points from 2020 to 2025 (median AQI -1).
Median AQI
Median AQI: 27

Aggregated from EPA Air Quality System (2025), 360 monitored days. EPA AQS →

The verdict

Aberdeen, SD sits in the upper Good-day tercile among EPA CBSA metros on this site (83.6% of 360 monitored days). On the EPA scale the metro runs good, cleaner than most US metros, with a median AQI of 27 and 83.6% of 360 monitored days in the Good band.

27
median AQI · Good
83.6%
days rated Good
75%
cleaner than US metros
115
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Aberdeen, SD metro's Good-day share fell from 86.7% to 85.0% between the 2024 and 2025 EPA annual releases, a change of -1.7 percentage points.
  • Aberdeen, SD metro's median AQI rose from 24 to 27 between the 2024 and 2025 EPA annual releases, a change of +3 points.

Compared against 353 monitored days in 2024 and 354 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

Aberdeen, SD sits in the upper Good-day tercile among EPA CBSA metros on this site (83.6% of 360 monitored days). Signature read: 83.6% Good-day share (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 27 over 360 measured days in 2025 (Good / Good). The monitored-day split lands at 301 Good (84%), 53 Moderate (15%), and 6 Unhealthy-for-Sensitive-Groups (2%). The 90th-percentile AQI finished at 56; the highest single-day reading hit 115 (USG).

Across 2020–2025, Good-day share shifted +0.4 points and median AQI moved -1 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Albany, OR (80.0% good, AQI 27); Anchorage, AK (77.5% good, AQI 27); La Grande, OR (84.4% good, AQI 27).

Best and worst city air quality →

Air Quality Summary

Median AQI

27

Good

Good Days

83.6%

301 of 360 days

Max AQI

115

USG

Health Grade

Good

90th pct: 56

AQI Day Breakdown (2025)

Distribution of 360 monitored days across EPA AQI categories.

Good

301

84%

Moderate

53

15%

USG

6

2%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Aberdeen, SD metro area's air quality is rated Good based on 83.6% good air days. No unhealthy air days were recorded in 2025.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Aberdeen, SD metro compare?

How Aberdeen, SD compares

Good-day share better than typical
Aberdeen, SD 83.6%
Albany, OR 80.0%
Typical US metro 70.6%
Median AQI better than typical
Aberdeen, SD 27
Albany, OR 27
Typical US metro 41
Unhealthy days / yr better than typical
Aberdeen, SD 0
Albany, OR 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Aberdeen, SD metro. Highest Good-day share: 2022 (92.9%, 325 of 350 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 308 56 0 28
2021 301 52 2 26
2022 325 25 0 23
2023 289 68 1 29
2024 306 47 0 24
2025 301 53 0 27

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Aberdeen, SD (27).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Aberdeen, SD's 0 (independent of median AQI).

Frequently Asked Questions

How many unhealthy air days does Aberdeen, SD have?
In 2025, the Aberdeen, SD metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 115.
What is the air quality in the Aberdeen, SD metro area?
The Aberdeen, SD metro area has a median Air Quality Index (AQI) of 27, rated "Good." 83.6% of monitored days (301 out of 360) had good air quality in 2025.
Is air quality in Aberdeen, SD getting better or worse?
Air quality in the Aberdeen, SD metro is stable across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2022 at 92.9% (325 of 350 days). Lowest qualifying Good-day share: 2023 at 80.7% (289 of 358 days).
What does AQI 27 mean for health?
An AQI of 27 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
How does Aberdeen, SD compare to other metro areas?
The Aberdeen, SD metro has 83.6% good air days. Similar metros: Albany, OR (80.0% good), Anchorage, AK (77.5% good), La Grande, OR (84.4% good).
What is the 90th percentile AQI for Aberdeen, SD?
The 90th percentile AQI for the Aberdeen, SD metro area is 56, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 115 (USG).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Aberdeen, SD, 2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Aberdeen, SD · 2020–2025