Metro area air quality · 2024

Jefferson City, MO

Median AQI 40 (Good). 95.0% of monitored days rated Good across this metro's EPA monitoring network.

40
Median AQI
95.0%
Good-air days
0
Unhealthy days
93%
Cleaner than US metros

Aggregated from EPA Air Quality System (2024), 262 monitored days. EPA AQS → · NOAA →

Insights: Jefferson City, MO metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 40 over 262 measured days in 2024, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 249 Good days (95%), 13 Moderate (5%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 49 while the highest single-day reading hit 77 (Moderate). Metro residents averaged roughly 28.5 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by +15 and the median AQI moved +5 points, which classifies the multi-year trajectory as improving. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Bismarck, ND (73.0% good, AQI 40); Cambridge, MD (80.3% good, AQI 40); Charleston, WV (77.8% good, AQI 40).

Air Quality Summary

Median AQI

40

Good

Good Days

95.0%

249 of 262 days

Max AQI

77

Moderate

Health Grade

Excellent

90th pct: 49

AQI Day Breakdown (2024)

Distribution of 262 monitored days across EPA AQI categories.

Good

249

95%

Moderate

13

5%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The Jefferson City, MO metro area's air quality is rated Excellent based on 95.0% good air days. No unhealthy air days were recorded in 2024.

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 US avg
Jefferson City, MO 95.0%
Bismarck, ND 73.0%
US average 70.2%
Median AQI better than US avg
Jefferson City, MO 40
Bismarck, ND 40
US average 41
Unhealthy days / yr better than US avg
Jefferson City, MO 0
Bismarck, ND 2
US average 1

5-Year Air Quality Trend

Air quality is improving in the Jefferson City, MO metro. Best year: 2024 (249 good 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

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Jefferson City, MO.

Bismarck, ND

AQI 40 · 73.0% good

40

Cambridge, MD

AQI 40 · 80.3% good

40

Charleston, WV

AQI 40 · 77.8% good

40

Charlottesville, VA

AQI 40 · 78.9% good

40

Daphne-Fairhope-Foley, AL

AQI 40 · 78.3% good

40

Hartford-West Hartford-East Hartford, CT

AQI 40 · 75.4% good

40

More Air Quality Data

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Worst Air Quality

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All Metro Areas

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Best and Worst City Air

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Air Quality Guides

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Understanding AQI

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Best & Worst City Air Quality

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Health Effects of Air Pollution

How PM2.5 and ozone exposure affects respiratory and cardiovascular health.

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 40, rated "Good." 95.0% of monitored days (249 out of 262) had good air quality in 2024.
How many unhealthy air days does Jefferson City, MO have? ▼
In 2024, 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 improving based on 5-year trends (2020-2024). Best year: 2024 with 249 good days. Worst year: 2023 with 197 good days.
What does AQI 40 mean for health? ▼
An AQI of 40 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 49, 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 95.0% good air days. Similar metros: Bismarck, ND (73.0% good), Cambridge, MD (80.3% good), Charleston, WV (77.8% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2024. The AQS collects ambient air monitoring data from state, local, and tribal monitoring agencies across the United States.

Metrics: Air Quality Index (AQI) is calculated using EPA-standard breakpoints for six criteria pollutants: PM2.5, PM10, Ozone, NO2, CO, and SO2. Median AQI, max AQI, and 90th percentile AQI are computed from daily measurements. Good days percentage reflects days with AQI 0–50.

Coverage: 501 metro areas (Core Based Statistical Areas). Only metros with active monitoring stations are included. Unmonitored areas are not represented.

Read our methodology , how this data is sourced, computed, and verified.

Source: U.S. EPA, AirNow / AQS Air Quality Index readings and pollutant concentrations · 2025