Metro area air quality · 2025
Vermillion, SD
Median AQI 34 (Good). 87.8% of monitored days rated Good across this metro's EPA monitoring network.
- 34
- Median AQI
- 87.8%
- Good-air days
- 0
- Unhealthy days
- 83%
- Cleaner than US metros
Vermillion, SD posted a 2025 median AQI of 34 (Good) with 87.8% Good days
According to the U.S. EPA Air Quality System, the Vermillion, SD CBSA recorded a median AQI of 34 across 351 monitored days in 2025, with 87.8% 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 Vermillion, SD CBSA's 87.8% Good-day share places it cleaner than 83% of US metros in 2025.
- Closest median-AQI peer
- Arkadelphia, AR (96.7% Good, median AQI 34) is the closest nationwide median-AQI peer to Vermillion, SD.
- 2022–2025 Good-day shift
- Vermillion, SD's Good-day share moved +0.6 points from 2022 to 2025 (median AQI -4).
- Median AQI
- Median AQI: 34
Aggregated from EPA Air Quality System (2025), 351 monitored days. EPA AQS →
The verdict
Vermillion, SD sits in the upper Good-day tercile among EPA CBSA metros on this site (87.8% of 351 monitored days). On the EPA scale the metro runs good, cleaner than most US metros, with a median AQI of 34 and 87.8% of 351 monitored days in the Good band.
- 34
- median AQI · Good
- 87.8%
- days rated Good
- 83%
- cleaner than US metros
- 117
- 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
- Vermillion, SD metro's Good-day share rose from 79.4% to 88.3% between the 2024 and 2025 EPA annual releases, a change of +8.9 percentage points.
- Vermillion, SD metro's peak single-day AQI fell from 137 to 117 between the 2024 and 2025 EPA annual releases, a change of -20 points.
- Vermillion, SD metro's median AQI fell from 39 to 34 between the 2024 and 2025 EPA annual releases, a change of -5 points.
Vermillion, SD sits in the upper Good-day tercile among EPA CBSA metros on this site (87.8% of 351 monitored days). Signature read: 87.8% 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 34 over 351 measured days in 2025 (Good / Good). The monitored-day split lands at 308 Good (88%), 41 Moderate (12%), and 2 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 53; the highest single-day reading hit 117 (USG).
Across 2022–2025, Good-day share shifted +0.6 points and median AQI moved -4 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Arkadelphia, AR (96.7% good, AQI 34); Augusta-Waterville, ME (85.2% good, AQI 34); Beatrice, NE (75.8% good, AQI 34).
Air Quality Summary
Median AQI
34
Good
Good Days
87.8%
308 of 351 days
Max AQI
117
USG
Health Grade
Good
90th pct: 53
AQI Day Breakdown (2025)
Distribution of 351 monitored days across EPA AQI categories.
Good
308
88%
Moderate
41
12%
USG
2
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Vermillion, SD metro area's air quality is rated Good based on 87.8% 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 Vermillion, SD metro compare?
How Vermillion, SD compares
5-Year Air Quality Trend
Air quality is stable in the Vermillion, SD metro. Highest Good-day share: 2025 (88.3%, 308 of 349 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2022 | 320 | 45 | 0 | 38 | 87 |
| 2023 | 244 | 103 | 3 | 43 | 173 |
| 2024 | 289 | 75 | 0 | 39 | 137 |
| 2025 | 308 | 41 | 0 | 34 | 117 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Vermillion, SD (34).
Arkadelphia, AR
Median AQI 34 · 96.7% Good-day share
Augusta-Waterville, ME
Median AQI 34 · 85.2% Good-day share
Beatrice, NE
Median AQI 34 · 75.8% Good-day share
Dyersburg, TN
Median AQI 34 · 76.9% Good-day share
Erie, PA
Median AQI 34 · 76.7% Good-day share
Grand Island, NE
Median AQI 34 · 82.5% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Vermillion, SD's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Aberdeen, WA
0 unhealthy-or-worse days · median AQI 22
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, GA
0 unhealthy-or-worse days · median AQI 46
Albany, OR
0 unhealthy-or-worse days · median AQI 27
Frequently Asked Questions
How many unhealthy air days does Vermillion, SD have? ▼
What is the air quality in the Vermillion, SD metro area? ▼
Is air quality in Vermillion, SD getting better or worse? ▼
What does AQI 34 mean for health? ▼
How does Vermillion, SD compare to other metro areas? ▼
What is the 90th percentile AQI for Vermillion, SD? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Vermillion, SD, 2025. See our methodology for how AQI, median, and coverage figures are computed.
Read our methodology , how this data is sourced, computed, and verified.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary, Vermillion, SD · 2020–2025