Metro area air quality · 2025

Jefferson City, MO

Median AQI 41 (Good). 89.6% of monitored days rated Good across this metro's EPA monitoring network.

41
Median AQI
89.6%
Good-air days
0
Unhealthy days
85%
Cleaner than US metros

Jefferson City, MO posted a 2025 median AQI of 41 (Good) with 89.6% Good days

According to the U.S. EPA Air Quality System, the Jefferson City, MO CBSA recorded a median AQI of 41 across 260 monitored days in 2025, with 89.6% 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 Jefferson City, MO CBSA's 89.6% Good-day share places it cleaner than 85% of US metros in 2025.
Closest median-AQI peer
Adrian, MI (69.3% Good, median AQI 41) is the closest nationwide median-AQI peer to Jefferson City, MO.
2020–2025 Good-day shift
Jefferson City, MO's Good-day share moved -5.9 points from 2020 to 2025 (median AQI +6).
Median AQI
Median AQI: 41

Aggregated from EPA Air Quality System (2025), 260 monitored days. EPA AQS →

The verdict

The Jefferson City, MO metro runs good on the EPA scale, cleaner than most US metros, a median AQI of 41 with 89.6% of 260 monitored days in the Good band.

41
median AQI · Good
89.6%
days rated Good
85%
cleaner than US metros
77
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
  • Jefferson City, MO metro's Good-day share fell from 95.0% to 89.6% between the 2024 and 2025 EPA annual releases, a change of -5.4 percentage points.

Compared against 262 monitored days in 2024 and 260 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

Insights: Jefferson City, MO metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 41 over 260 measured days in 2025, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 233 Good days (90%), 27 Moderate (10%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 51 while the highest single-day reading hit 77 (Moderate). Metro residents averaged roughly 26.9 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 -5.9 points (measured against 245 monitored days in 2020 and 260 in 2025, so raw day counts are not comparable) and the median AQI moved +6 points, which classifies the multi-year trajectory as worsening. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Adrian, MI (69.3% good, AQI 41); Albany-Schenectady-Troy, NY (67.7% good, AQI 41); Ann Arbor, MI (69.3% good, AQI 41).

Air Quality Summary

Median AQI

41

Good

Good Days

89.6%

233 of 260 days

Max AQI

77

Moderate

Health Grade

Good

90th pct: 51

AQI Day Breakdown (2025)

Distribution of 260 monitored days across EPA AQI categories.

Good

233

90%

Moderate

27

10%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Jefferson City, MO metro area's air quality is rated Good based on 89.6% 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 Jefferson City, MO metro compare?

How Jefferson City, MO compares

Good-day share better than typical
Jefferson City, MO 89.6%
Adrian, MI 69.3%
Typical US metro 70.6%
Median AQI about typical
Jefferson City, MO 41
Adrian, MI 41
Typical US metro 41
Unhealthy days / yr better than typical
Jefferson City, MO 0
Adrian, MI 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is worsening in the Jefferson City, MO metro. Highest Good-day share: 2020 (95.5%, 234 of 245 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 234 11 0 35
2021 229 16 0 39
2022 222 22 0 40
2023 197 43 0 43
2024 249 13 0 40
2025 233 27 0 41

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Jefferson City, MO (41).

Metros with similar unhealthy-day exposure

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

More Air Quality Data

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

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Jefferson City, MO metro area?
The Jefferson City, MO metro area has a median Air Quality Index (AQI) of 41, rated "Good." 89.6% of monitored days (233 out of 260) had good air quality in 2025.
How many unhealthy air days does Jefferson City, MO have?
In 2025, the Jefferson City, MO metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 77.
Is air quality in Jefferson City, MO getting better or worse?
Air quality in the Jefferson City, MO 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 95.5% (234 of 245 days). Lowest qualifying Good-day share: 2023 at 82.1% (197 of 240 days).
What does AQI 41 mean for health?
An AQI of 41 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 Jefferson City, MO?
The 90th percentile AQI for the Jefferson City, MO metro area is 51, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 77 (Moderate).
How does Jefferson City, MO compare to other metro areas?
The Jefferson City, MO metro has 89.6% good air days. Similar metros: Adrian, MI (69.3% good), Albany-Schenectady-Troy, NY (67.7% good), Ann Arbor, MI (69.3% 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.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025

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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.