North Carolina · County air quality · 2025

Macon County, North Carolina

Median AQI 34 (Good). 94.7% of monitored days rated Good, direct from EPA Air Quality System stations.

34
Median AQI
94.7%
Good-air days
0
Unhealthy days
88%
Cleaner than US counties

The verdict

According to EPA Air Quality System monitoring data, Macon County's air is good on balance, cleaner than most US counties, a median AQI of 34 with 94.7% of 227 monitored days in the Good band, driven mainly by Ozone.

34
median AQI · Good
94.7%
days rated Good
Ozone
main pollutant
88%
cleaner than US counties

Not one day crossed into the Unhealthy tier; the worst single reading was AQI 97.

Data updated July 2026

Macon County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 227 monitored days G Median AQI 34 0 50 100 150 200 300 500 Macon County
  • Good · 215 d · 94.7%
  • Moderate · 12 d · 5.3%

How did Macon County's air break down in 2025?

Across 227 monitored days, 215 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 97 (Moderate).

EPA AQS →

Air quality data from EPA Air Quality System (2025). 227 days monitored. Median AQI: 34 (Good).

Insights: Macon County, North Carolina. EPA monitors recorded a median Air Quality Index of 34 across 227 measured days in 2025, earning a Good classification and a Excellent health grade. Of those days, 215 (95%) fell in the Good band (AQI 0–50), 12 (5%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 47, while the worst single-day peak hit 97 (Moderate). Residents averaged about 28.4 clean-air days per 30-day window during the monitoring year.

The full pollutant mix ranks as Ozone (227 days). Across the 2020–2025 trend window, good days shifted by -143 and the median AQI moved +5 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 97, moderate but never Unhealthy. Nearby counties show comparable readings: Alexander (92.4% good, AQI 39); Avery (93.9% good, AQI 38); Buncombe (71.4% good, AQI 42); Caldwell (96.2% good, AQI 37); Carteret (94.2% good, AQI 37); Caswell (94.6% good, AQI 39).

Air Quality Summary

Median AQI

34

Good

Good Days

94.7%

215 of 227 monitored days

19.7pp vs 75% target

Max AQI Recorded

97

Moderate

Health Grade

Excellent

90th-pct AQI 47

Macon County, Good days share 94.7%
National avg

Share of monitored days at AQI 0-50 (Good band).

Macon County, Unhealthy-or-worse share 0.0%
National avg

Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).

AQI Day Breakdown (2025)

Distribution of 227 monitored days across EPA AQI categories.

Good

215

95%

Moderate

12

5%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Macon County.

Macon County, North Carolina criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. Ozone · 100.0% 0% 25% 50% 75% 100% Macon County, North Carolina · 227 monitored days Criteria pollutant column
  • Ozone · 227 days · 100.0%
Ozone (O3) 227 days (100%)

How Ozone affects health →

Health Impact Assessment

Excellent

Macon County's air quality is rated Excellent based on 94.7% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 94.7% of monitored days in 2025, with a median AQI of 34. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is Ozone, driving AQI on 227 of 227 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Macon County. Best year: 2020 (358 good days).

Year Good Moderate USG Unhealthy Median AQI
2020 358 2 0 0 29
2021 347 12 0 0 30
2022 349 11 0 0 31
2023 342 19 0 0 34
2024 348 14 0 0 34
2025 215 12 0 0 34

How does Macon County compare?

How Macon County compares

Good-day share better than US avg
Macon County 94.7%
Alexander County, North Carolina 92.4%
US average 76.5%
Median AQI better than US avg
Macon County 34
Alexander County, North Carolina 39
US average 38
Unhealthy days / yr about average
Macon County 0
Alexander County, North Carolina 0
US average 0

Other Counties in North Carolina

Air quality comparison for nearby counties in North Carolina.

Counties with Similar Air Quality

Counties across the US with a similar median AQI to Macon County.

What Macon County's air means for you

The air here stays in the breathable range year-round, with Ozone the main thing to watch.

  • Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 34 means for exposure. Health guidance
  • See how Macon County ranks against every monitored U.S. county on Good-day share. County rankings
  • Compare Macon County with its North Carolina neighbours before drawing a conclusion about the region. All of North Carolina

Based on 227 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.

More Air Quality Data

Air Quality Guides

Frequently Asked Questions

What is the air quality in Macon County, North Carolina?
Macon County has a median Air Quality Index (AQI) of 34, rated "Good." 94.7% of monitored days (215 out of 227) had good air quality in 2025.
What is the main pollutant in Macon County?
The primary pollutant in Macon County is Ozone (O3), which was the main AQI driver on 227 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Macon County have?
In 2025, Macon County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 97.
Is the air quality in Macon County getting better or worse?
Air quality in Macon County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 358 good days. Worst year: 2025 with 215 good days.
What does AQI 34 mean for health?
Macon County's median AQI of 34 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Macon County compare to other counties in North Carolina?
Macon County has 94.7% good air days. Nearby counties in North Carolina: Alexander (92.4% good), Avery (93.9% good), Buncombe (71.4% good), Caldwell (96.2% good), Carteret (94.2% good), Caswell (94.6% good).
What is the 90th percentile AQI in Macon County?
The 90th percentile AQI for Macon County is 47, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 97 (Moderate).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.

Informational only, not professional advice. Data from EPA AQS. See our disclaimer.

Every figure on PlainAir 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.