Metro area air quality · 2025

Pierre, SD

Median AQI 18 (Good). 93.0% of monitored days rated Good across this metro's EPA monitoring network.

18
Median AQI
93.0%
Good-air days
0
Unhealthy days
91%
Cleaner than US metros

Pierre, SD posted a 2025 median AQI of 18 (Good) with 93.0% Good days

According to the U.S. EPA Air Quality System, the Pierre, SD CBSA recorded a median AQI of 18 across 358 monitored days in 2025, with 93.0% 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 Pierre, SD CBSA's 93.0% Good-day share places it cleaner than 91% of US metros in 2025.
Closest median-AQI peer
Deming, NM (84.7% Good, median AQI 17) is the closest nationwide median-AQI peer to Pierre, SD.
2020–2025 Good-day shift
Pierre, SD's Good-day share moved -0.2 points from 2020 to 2025 (median AQI -1).
Median AQI
Median AQI: 18

Aggregated from EPA Air Quality System (2025), 358 monitored days. EPA AQS →

The verdict

Pierre, SD sits in the upper Good-day tercile among EPA CBSA metros on this site (93.0% of 358 monitored days). On the EPA scale the metro runs good, among the cleanest 10% of US metros, with a median AQI of 18 and 93.0% of 358 monitored days in the Good band.

18
median AQI · Good
93.0%
days rated Good
91%
cleaner than US metros
112
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
  • Pierre, SD metro's peak single-day AQI rose from 69 to 112 between the 2024 and 2025 EPA annual releases, a change of +43 points.
  • Pierre, SD metro's median AQI rose from 8 to 18 between the 2024 and 2025 EPA annual releases, a change of +10 points.

Compared against 363 monitored days in 2024 and 357 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

Pierre, SD sits in the upper Good-day tercile among EPA CBSA metros on this site (93.0% of 358 monitored days). Signature read: 93.0% 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 18 over 358 measured days in 2025 (Good / Excellent). The monitored-day split lands at 333 Good (93%), 24 Moderate (7%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 45; the highest single-day reading hit 112 (USG).

Across 2020–2025, Good-day share shifted -0.2 points and median AQI moved -1 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Deming, NM (84.7% good, AQI 17); Hailey, ID (96.6% good, AQI 17); Lake Havasu City-Kingman, AZ (94.8% good, AQI 17).

Best and worst city air quality →

Air Quality Summary

Median AQI

18

Good

Good Days

93.0%

333 of 358 days

Max AQI

112

USG

Health Grade

Excellent

90th pct: 45

AQI Day Breakdown (2025)

Distribution of 358 monitored days across EPA AQI categories.

Good

333

93%

Moderate

24

7%

USG

1

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The Pierre, SD metro area's air quality is rated Excellent based on 93.0% 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 Pierre, SD metro compare?

How Pierre, SD compares

Good-day share better than typical
Pierre, SD 93.0%
Deming, NM 84.7%
Typical US metro 70.6%
Median AQI better than typical
Pierre, SD 18
Deming, NM 17
Typical US metro 41
Unhealthy days / yr better than typical
Pierre, SD 0
Deming, NM 9
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Pierre, SD metro. Highest Good-day share: 2022 (97.2%, 352 of 362 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 332 23 0 19
2021 325 22 0 12
2022 352 10 0 7
2023 321 30 4 14
2024 340 23 0 8
2025 333 24 0 18

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Pierre, SD (18).

Metros with similar unhealthy-day exposure

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

Frequently Asked Questions

How many unhealthy air days does Pierre, SD have? ▼
In 2025, the Pierre, SD metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 112.
What is the air quality in the Pierre, SD metro area? ▼
The Pierre, SD metro area has a median Air Quality Index (AQI) of 18, rated "Good." 93.0% of monitored days (333 out of 358) had good air quality in 2025.
Is air quality in Pierre, SD getting better or worse? ▼
Air quality in the Pierre, 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 97.2% (352 of 362 days). Lowest qualifying Good-day share: 2023 at 90.4% (321 of 355 days).
What does AQI 18 mean for health? ▼
An AQI of 18 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 Pierre, SD compare to other metro areas? ▼
The Pierre, SD metro has 93.0% good air days. Similar metros: Deming, NM (84.7% good), Hailey, ID (96.6% good), Lake Havasu City-Kingman, AZ (94.8% good).
What is the 90th percentile AQI for Pierre, SD? ▼
The 90th percentile AQI for the Pierre, SD metro area is 45, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 112 (USG).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Pierre, 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, Pierre, SD · 2020–2025