Median AQI
46
Good
North Carolina · County air quality · 2025
Forsyth County, North Carolina
Median AQI 46 (Good). 61.7% of monitored days rated Good, direct from EPA Air Quality System stations.
- 46
- Median AQI
- 61.7%
- Good-air days
- 0
- Unhealthy days
- 18%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Forsyth County's air is good on balance, among the more polluted 10% of US counties, a median AQI of 46 with 61.7% of 243 monitored days in the Good band, driven mainly by PM2.5.
- 46
- median AQI · Good
- 61.7%
- days rated Good
- PM2.5
- main pollutant
- 18%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 90.
Data updated July 2026
- Good · 150 d · 61.7%
- Moderate · 93 d · 38.3%
How did Forsyth County's air break down in 2025?
Across 243 monitored days, 150 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 90 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 243 days monitored. Median AQI: 46 (Good).
Insights: Forsyth County, North Carolina. EPA monitors recorded a median Air Quality Index of 46 across 243 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 150 (62%) fell in the Good band (AQI 0–50), 93 (38%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 66, while the worst single-day peak hit 90 (Moderate). Residents averaged about 18.5 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (131 days), Ozone (111 days), NO2 (1 days). Across the 2020–2025 trend window, good days shifted by -83 and the median AQI moved +1 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 90, 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
61.7%
150 of 243 monitored days
-13.3pp vs 75% target
Max AQI Recorded
90
Moderate
Health Grade
Moderate
90th-pct AQI 66
Forsyth County, Good days share 61.7%
National avg
Share of monitored days at AQI 0-50 (Good band).
Forsyth 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 243 monitored days across EPA AQI categories.
Good
150
62%
Moderate
93
38%
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 Forsyth County.
- PM2.5 · 131 days · 53.9%
- Ozone · 111 days · 45.7%
- NO₂ · 1 days · 0.4%
Health Impact Assessment
Moderate
Forsyth County's air quality is rated Moderate based on 61.7% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 61.7% of monitored days in 2025, with a median AQI of 46. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 131 of 243 monitored days.
5-Year Air Quality Trend
Air quality is stable in Forsyth County. Best year: 2020 (233 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 233 | 133 | 0 | 0 | 45 | 97 |
| 2021 | 201 | 161 | 3 | 0 | 48 | 124 |
| 2022 | 209 | 155 | 1 | 0 | 48 | 137 |
| 2023 | 165 | 193 | 6 | 1 | 52 | 154 |
| 2024 | 210 | 152 | 4 | 0 | 47 | 122 |
| 2025 | 150 | 93 | 0 | 0 | 46 | 90 |
How does Forsyth County compare?
How Forsyth County compares
Good-day share worse than US avg
Forsyth County 61.7%
Alexander County, North Carolina 92.4%
US average 76.5%
Median AQI worse than US avg
Forsyth County 46
Alexander County, North Carolina 39
US average 38
Unhealthy days / yr about average
Forsyth 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 Forsyth County.
Bay County, Florida
AQI 46 · 60.6% good
Blount County, Tennessee
AQI 46 · 69.6% good
Cache County, Utah
AQI 46 · 61.2% good
Chesterfield County, South Carolina
AQI 46 · 61.2% good
Clark County, Indiana
AQI 46 · 59.7% good
Clark County, Ohio
AQI 46 · 59.4% good
What Forsyth County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 46 means for exposure. Health guidance
- See how Forsyth County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Forsyth County with its North Carolina neighbours before drawing a conclusion about the region. All of North Carolina
Based on 243 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 Forsyth County, North Carolina? ▼
Forsyth County has a median Air Quality Index (AQI) of 46, rated "Good." 61.7% of monitored days (150 out of 243) had good air quality in 2025.
What is the main pollutant in Forsyth County? ▼
The primary pollutant in Forsyth County is Fine Particles (PM2.5), which was the main AQI driver on 131 days (54% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Forsyth County have? ▼
In 2025, Forsyth County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 90.
Is the air quality in Forsyth County getting better or worse? ▼
Air quality in Forsyth County is stable based on 5-year trends (2020-2025). Best year: 2020 with 233 good days. Worst year: 2025 with 150 good days.
What does AQI 46 mean for health? ▼
Forsyth County's median AQI of 46 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 Forsyth County compare to other counties in North Carolina? ▼
Forsyth County has 61.7% 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 Forsyth County? ▼
The 90th percentile AQI for Forsyth County is 66, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 90 (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.