Metro area air quality · 2025

Burlington-South Burlington, VT

Median AQI 38 (Good). 87.7% of monitored days rated Good across this metro's EPA monitoring network.

38
Median AQI
87.7%
Good-air days
1
Unhealthy days
82%
Cleaner than US metros

Burlington-South Burlington, VT posted a 2025 median AQI of 38 (Good) with 87.7% Good days

According to the U.S. EPA Air Quality System, the Burlington-South Burlington, VT CBSA recorded a median AQI of 38 across 365 monitored days in 2025, with 87.7% rated Good and 1 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 Burlington-South Burlington, VT CBSA's 87.7% Good-day share places it cleaner than 82% of US metros in 2025.
Closest median-AQI peer
Appleton, WI (72.3% Good, median AQI 38) is the closest nationwide median-AQI peer to Burlington-South Burlington, VT.
2020–2025 Good-day shift
Burlington-South Burlington, VT's Good-day share moved +5.9 points from 2020 to 2025 (median AQI -1).
Median AQI
Median AQI: 38

Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →

The verdict

Burlington-South Burlington, VT sits in the upper Good-day tercile among EPA CBSA metros on this site (87.7% of 365 monitored days). On the EPA scale the metro runs good, cleaner than most US metros, with a median AQI of 38 and 87.7% of 365 monitored days in the Good band.

38
median AQI · Good
87.7%
days rated Good
82%
cleaner than US metros
156
worst single reading

1 day reached Unhealthy or worse across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Burlington-South Burlington, VT metro's peak single-day AQI rose from 84 to 156 between the 2024 and 2025 EPA annual releases, a change of +72 points.
  • Burlington-South Burlington, VT metro's Unhealthy-category days rose from 0 to 1 between the 2024 and 2025 EPA annual releases, a change of +1 days.

Compared against 366 monitored days in 2024 and 362 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

Burlington-South Burlington, VT sits in the upper Good-day tercile among EPA CBSA metros on this site (87.7% of 365 monitored days). Signature read: 87.7% 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 38 over 365 measured days in 2025 (Good / Good). The monitored-day split lands at 320 Good (88%), 41 Moderate (11%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 55; the highest single-day reading hit 156 (Unhealthy).

Across 2020–2025, Good-day share shifted +5.9 points and median AQI moved -1 (improving). The annual record contains 1 day at Unhealthy or worse. Metros with comparable AQI profiles include Appleton, WI (72.3% good, AQI 38); Billings, MT (86.3% good, AQI 38); Charlottesville, VA (81.0% good, AQI 38).

Health effects of air pollution →

Air Quality Summary

Median AQI

38

Good

Good Days

87.7%

320 of 365 days

Max AQI

156

Unhealthy

Health Grade

Good

90th pct: 55

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

320

88%

Moderate

41

11%

USG

3

1%

Unhealthy

1

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Burlington-South Burlington, VT metro area's air quality is rated Good based on 87.7% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.

Air quality is acceptable most days, but 3 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 156. Sensitive groups should monitor real-time conditions at AirNow.gov.

How does the Burlington-South Burlington, VT metro compare?

How Burlington-South Burlington, VT compares

Good-day share better than typical
Burlington-South Burlington, VT 87.7%
Appleton, WI 72.3%
Typical US metro 70.6%
Median AQI better than typical
Burlington-South Burlington, VT 38
Appleton, WI 38
Typical US metro 41
Unhealthy days / yr about typical
Burlington-South Burlington, VT 1
Appleton, WI 6
Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Burlington-South Burlington, VT metro. Highest Good-day share: 2025 (88.4%, 320 of 362 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 302 64 0 39
2021 288 76 0 40
2022 298 67 0 41
2023 259 100 2 42
2024 323 43 0 37
2025 320 41 1 38

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Burlington-South Burlington, VT (38).

Appleton, WI

Median AQI 38 · 72.3% Good-day share

38

Billings, MT

Median AQI 38 · 86.3% Good-day share

38

Charlottesville, VA

Median AQI 38 · 81.0% Good-day share

38

Corning, NY

Median AQI 38 · 83.3% Good-day share

38

Dickinson, ND

Median AQI 38 · 82.7% Good-day share

38

Eau Claire, WI

Median AQI 38 · 73.7% Good-day share

38

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Burlington-South Burlington, VT's 1 (independent of median AQI).

Ann Arbor, MI

1 unhealthy-or-worse days · median AQI 41

41

Bangor, ME

1 unhealthy-or-worse days · median AQI 33

33

Baraboo, WI

1 unhealthy-or-worse days · median AQI 35

35

Bartlesville, OK

1 unhealthy-or-worse days · median AQI 44

44

Beaumont-Port Arthur, TX

1 unhealthy-or-worse days · median AQI 52

52

Beaver Dam, WI

1 unhealthy-or-worse days · median AQI 40

40

Frequently Asked Questions

How many unhealthy air days does Burlington-South Burlington, VT have? ▼
In 2025, the Burlington-South Burlington, VT metro area recorded 1 unhealthy air days (1 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 156.
What is the air quality in the Burlington-South Burlington, VT metro area? ▼
The Burlington-South Burlington, VT metro area has a median Air Quality Index (AQI) of 38, rated "Good." 87.7% of monitored days (320 out of 365) had good air quality in 2025.
Is air quality in Burlington-South Burlington, VT getting better or worse? ▼
Air quality in the Burlington-South Burlington, VT metro is improving across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2025 at 88.4% (320 of 362 days). Lowest qualifying Good-day share: 2023 at 71.7% (259 of 361 days).
What does AQI 38 mean for health? ▼
An AQI of 38 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 Burlington-South Burlington, VT compare to other metro areas? ▼
The Burlington-South Burlington, VT metro has 87.7% good air days. Similar metros: Appleton, WI (72.3% good), Billings, MT (86.3% good), Charlottesville, VA (81.0% good).
What is the 90th percentile AQI for Burlington-South Burlington, VT? ▼
The 90th percentile AQI for the Burlington-South Burlington, VT metro area is 55, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 156 (Unhealthy).

Data Sources

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