Metro area air quality · 2025

Flagstaff, AZ

Median AQI 46 (Good). 70.1% of monitored days rated Good across this metro's EPA monitoring network.

46
Median AQI
70.1%
Good-air days
0
Unhealthy days
46%
Cleaner than US metros

Flagstaff, AZ posted a 2025 median AQI of 46 (Good) with 70.1% Good days

According to the U.S. EPA Air Quality System, the Flagstaff, AZ CBSA recorded a median AQI of 46 across 365 monitored days in 2025, with 70.1% 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 Flagstaff, AZ CBSA's 70.1% Good-day share places it cleaner than 46% of US metros in 2025.
Closest median-AQI peer
Albany, GA (57.3% Good, median AQI 46) is the closest nationwide median-AQI peer to Flagstaff, AZ.
2020–2025 Good-day shift
Flagstaff, AZ's Good-day share moved -12.0 points from 2020 to 2025 (median AQI +2).
Median AQI
Median AQI: 46

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

The verdict

Flagstaff, AZ's median AQI 46 is in the upper (dirtier) CBSA tercile on this site. On the EPA scale the metro runs good, more polluted than the median US metro, with a median AQI of 46 and 70.1% of 365 monitored days in the Good band.

46
median AQI · Good
70.1%
days rated Good
46%
cleaner than US metros
113
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
  • Flagstaff, AZ metro's peak single-day AQI fell from 136 to 113 between the 2024 and 2025 EPA annual releases, a change of -23 points.
  • Flagstaff, AZ metro's Good-day share rose from 69.3% to 70.5% between the 2024 and 2025 EPA annual releases, a change of +1.3 percentage points.

Compared against 361 monitored days in 2024 and 363 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

Flagstaff, AZ's median AQI 46 is in the upper (dirtier) CBSA tercile on this site. Signature read: median AQI 46 (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 46 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 256 Good (70%), 107 Moderate (29%), and 2 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 71; the highest single-day reading hit 113 (USG).

Across 2020–2025, Good-day share shifted -12.0 points and median AQI moved +2 (worsening). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Albany, GA (57.3% good, AQI 46); Athens-Clarke County, GA (57.8% good, AQI 46); Brookings, SD (58.6% good, AQI 46).

Health effects of air pollution →

Air Quality Summary

Median AQI

46

Good

Good Days

70.1%

256 of 365 days

Max AQI

113

USG

Health Grade

Moderate

90th pct: 71

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

256

70%

Moderate

107

29%

USG

2

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Flagstaff, AZ metro area's air quality is rated Moderate based on 70.1% 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 Flagstaff, AZ metro compare?

How Flagstaff, AZ compares

Good-day share about typical
Flagstaff, AZ 70.1%
Albany, GA 57.3%
Typical US metro 70.6%
Median AQI worse than typical
Flagstaff, AZ 46
Albany, GA 46
Typical US metro 41
Unhealthy days / yr better than typical
Flagstaff, AZ 0
Albany, GA 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is worsening in the Flagstaff, AZ metro. Highest Good-day share: 2020 (82.5%, 302 of 366 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 302 64 0 44
2021 265 100 0 46
2022 279 85 0 44
2023 243 118 2 46
2024 250 111 0 46
2025 256 107 0 46

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Flagstaff, AZ (46).

Albany, GA

Median AQI 46 · 57.3% Good-day share

46

Athens-Clarke County, GA

Median AQI 46 · 57.8% Good-day share

46

Brookings, SD

Median AQI 46 · 58.6% Good-day share

46

Chico, CA

Median AQI 46 · 65.2% Good-day share

46

Colorado Springs, CO

Median AQI 46 · 68.2% Good-day share

46

Davenport-Moline-Rock Island, IA-IL

Median AQI 46 · 56.7% Good-day share

46

Metros with similar unhealthy-day exposure

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

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

45

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Albany-Schenectady-Troy, NY

0 unhealthy-or-worse days · median AQI 41

41

Frequently Asked Questions

What does AQI 46 mean for health? ▼
An AQI of 46 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 many unhealthy air days does Flagstaff, AZ have? ▼
In 2025, the Flagstaff, AZ metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 113.
What is the air quality in the Flagstaff, AZ metro area? ▼
The Flagstaff, AZ metro area has a median Air Quality Index (AQI) of 46, rated "Good." 70.1% of monitored days (256 out of 365) had good air quality in 2025.
Is air quality in Flagstaff, AZ getting better or worse? ▼
Air quality in the Flagstaff, AZ metro is worsening across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 82.5% (302 of 366 days). Lowest qualifying Good-day share: 2023 at 66.9% (243 of 363 days).
How does Flagstaff, AZ compare to other metro areas? ▼
The Flagstaff, AZ metro has 70.1% good air days. Similar metros: Albany, GA (57.3% good), Athens-Clarke County, GA (57.8% good), Brookings, SD (58.6% good).
What is the 90th percentile AQI for Flagstaff, AZ? ▼
The 90th percentile AQI for the Flagstaff, AZ metro area is 71, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 113 (USG).

Data Sources

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