Metro area air quality · 2025

Bozeman, MT

Median AQI 11 (Good). 98.1% of monitored days rated Good across this metro's EPA monitoring network.

Compiled by PlainAirData · August 23, 2026

11
Median AQI: 98.1%
Good-air days: 0
Unhealthy days: 99%
Cleaner than US metros

Bozeman, MT posted a 2025 median AQI of 11 (Good) with 98.1% Good days

According to the U.S. EPA Air Quality System, the Bozeman, MT CBSA recorded a median AQI of 11 across 365 monitored days in 2025, with 98.1% 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 Bozeman, MT CBSA's 98.1% Good-day share places it cleaner than 99% of US metros in 2025.
Closest median-AQI peer: Evanston, WY (100.0% Good, median AQI 9) is the closest nationwide median-AQI peer to Bozeman, MT.
2020–2025 Good-day shift: Bozeman, MT's Good-day share moved +16.8 points from 2020 to 2025 (median AQI -18).
Median AQI: Median AQI: 11

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

The verdict

The Bozeman, MT metro runs good on the EPA scale, among the cleanest 10% of US metros, a median AQI of 11 with 98.1% of 365 monitored days in the Good band.

11
median AQI · Good: 98.1%
days rated Good: 99%
cleaner than US metros: 70
worst single reading

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

Bozeman, MT metro's Good-day share rose from 90.1% to 98.1% between the 2024 and 2025 EPA annual releases, a change of +7.9 percentage points.
Bozeman, MT metro's median AQI fell from 18 to 11 between the 2024 and 2025 EPA annual releases, a change of -7 points.
Bozeman, MT metro's peak single-day AQI fell from 84 to 70 between the 2024 and 2025 EPA annual releases, a change of -14 points.

Insights: Bozeman, MT metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 11 over 365 measured days in 2025, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 358 Good days (98%), 7 Moderate (2%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 26 while the highest single-day reading hit 70 (Moderate). Metro residents averaged roughly 29.4 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +16.8 points and the median AQI moved -18 points, which classifies the multi-year trajectory as improving. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Evanston, WY (100.0% good, AQI 9); Mayaguez, PR (97.8% good, AQI 9); Santa Rosa, CA (100.0% good, AQI 9).

Air Quality Summary

Median AQI

Good

Good Days

98.1%

358 of 365 days

Max AQI

Moderate

Health Grade

Excellent

90th pct: 26

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

358

98%

Moderate

USG

Unhealthy

Very Unhealthy

Hazardous

Health Impact Assessment

Excellent

The Bozeman, MT metro area's air quality is rated Excellent based on 98.1% 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 Bozeman, MT metro compare?

How Bozeman, MT compares

Compare against

Good-day share better than typical

Bozeman, MT 98.1%

Evanston, WY 100.0%

Typical US metro 70.6%

Median AQI better than typical

Bozeman, MT 11

Evanston, WY 9

Typical US metro 41

Unhealthy days / yr better than typical

Bozeman, MT 0

Evanston, WY 0

Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Bozeman, MT metro. Highest Good-day share: 2025 (98.1%, 358 of 365 monitored days).

Year	Good	Moderate	Unhealthy	Median AQI	Max AQI
2020	290	65	2	29	162
2021	243	107	1	41	158
2022	290	71	0	32	148
2023	331	34	0	26	98
2024	329	36	0	18	84
2025	358	7	0	11	70

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Bozeman, MT (11).

Evanston, WY

Median AQI 9 · 100.0% Good-day share

Mayaguez, PR

Median AQI 9 · 97.8% Good-day share

Santa Rosa, CA

Median AQI 9 · 100.0% Good-day share

Show Low, AZ

Median AQI 13 · 99.5% Good-day share

Havre, MT

Median AQI 14 · 92.1% Good-day share

Taos, NM

Median AQI 16 · 98.9% Good-day share

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Bozeman, MT'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

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Cleanest Metro Areas

U.S. metros ranked by their share of Good air-quality days.

Worst Air Quality

Counties and metros with the most unhealthy air days.

All Metro Areas

Annual AQI by CBSA for every monitored U.S. metro area.

Best and Worst City Air

What drives urban air quality and how metro areas compare.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Bozeman, MT metro area? ▼

The Bozeman, MT metro area has a median Air Quality Index (AQI) of 11, rated "Good." 98.1% of monitored days (358 out of 365) had good air quality in 2025.

How many unhealthy air days does Bozeman, MT have? ▼

In 2025, the Bozeman, MT metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 70.

Is air quality in Bozeman, MT getting better or worse? ▼

Air quality in the Bozeman, MT 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 98.1% (358 of 365 days). Lowest qualifying Good-day share: 2021 at 69.2% (243 of 351 days).

What does AQI 11 mean for health? ▼

An AQI of 11 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.

What is the 90th percentile AQI for Bozeman, MT? ▼

The 90th percentile AQI for the Bozeman, MT metro area is 26, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 70 (Moderate).

How does Bozeman, MT compare to other metro areas? ▼

The Bozeman, MT metro has 98.1% good air days. Similar metros: Evanston, WY (100.0% good), Mayaguez, PR (97.8% good), Santa Rosa, CA (100.0% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. 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 files (metro-level) · 2020–2025 Accessed 2026-07-06

Send the source-year summary or download its ready-to-use data card.

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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.