Median AQI
43
Good
North Carolina · County air quality · 2025
Graham County, North Carolina
Median AQI 43 (Good). 88.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 43
- Median AQI
- 88.6%
- Good-air days
- 0
- Unhealthy days
- 73%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Graham County's air is good on balance, cleaner than the median US county, a median AQI of 43 with 88.6% of 184 monitored days in the Good band, driven mainly by Ozone.
- 43
- median AQI · Good
- 88.6%
- days rated Good
- Ozone
- main pollutant
- 73%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 97.
Data updated July 2026
- Good · 163 d · 88.6%
- Moderate · 21 d · 11.4%
How did Graham County's air break down in 2025?
Across 184 monitored days, 163 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). 184 days monitored. Median AQI: 43 (Good).
Insights: Graham County, North Carolina. EPA monitors recorded a median Air Quality Index of 43 across 184 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 163 (89%) fell in the Good band (AQI 0–50), 21 (11%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 51, while the worst single-day peak hit 97 (Moderate). Residents averaged about 26.6 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (184 days). Across the 2020–2025 trend window, good days shifted by -60 and the median AQI moved +3 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
Good Days
88.6%
163 of 184 monitored days
13.6pp vs 75% target
Max AQI Recorded
97
Moderate
Health Grade
Good
90th-pct AQI 51
Graham County, Good days share 88.6%
National avg
Share of monitored days at AQI 0-50 (Good band).
Graham 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 184 monitored days across EPA AQI categories.
Good
163
89%
Moderate
21
11%
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 Graham County.
- Ozone · 184 days · 100.0%
Health Impact Assessment
Good
Graham County's air quality is rated Good based on 88.6% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 88.6% of monitored days in 2025, with a median AQI of 43. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 184 of 184 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Graham County. Best year: 2020 (223 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 223 | 15 | 0 | 0 | 40 | 97 |
| 2021 | 213 | 32 | 0 | 0 | 42 | 90 |
| 2022 | 200 | 41 | 3 | 0 | 43 | 112 |
| 2023 | 188 | 49 | 5 | 0 | 46 | 115 |
| 2024 | 199 | 52 | 0 | 0 | 44 | 90 |
| 2025 | 163 | 21 | 0 | 0 | 43 | 97 |
How does Graham County compare?
How Graham County compares
Good-day share better than US avg
Graham County 88.6%
Alexander County, North Carolina 92.4%
US average 76.5%
Median AQI worse than US avg
Graham County 43
Alexander County, North Carolina 39
US average 38
Unhealthy days / yr about average
Graham 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 Graham County.
Allegan County, Michigan
AQI 43 · 71.2% good
Allen County, Ohio
AQI 43 · 65.9% good
Ashtabula County, Ohio
AQI 43 · 81.2% good
Bell County, Kentucky
AQI 43 · 63.5% good
Boise County, Idaho
AQI 43 · 72.9% good
Brazos County, Texas
AQI 43 · 63.4% good
What Graham 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 43 means for exposure. Health guidance
- See how Graham County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Graham County with its North Carolina neighbours before drawing a conclusion about the region. All of North Carolina
Based on 184 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 Graham County, North Carolina? ▼
Graham County has a median Air Quality Index (AQI) of 43, rated "Good." 88.6% of monitored days (163 out of 184) had good air quality in 2025.
What is the main pollutant in Graham County? ▼
The primary pollutant in Graham County is Ozone (O3), which was the main AQI driver on 184 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Graham County have? ▼
In 2025, Graham County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 97.
Is the air quality in Graham County getting better or worse? ▼
Air quality in Graham County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 223 good days. Worst year: 2025 with 163 good days.
What does AQI 43 mean for health? ▼
Graham County's median AQI of 43 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 Graham County compare to other counties in North Carolina? ▼
Graham County has 88.6% 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 Graham County? ▼
The 90th percentile AQI for Graham County is 51, 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.