Median AQI
44
Good
South Carolina · County air quality · 2025
Edgefield County, South Carolina
Median AQI 44 (Good). 68.1% of monitored days rated Good, direct from EPA Air Quality System stations.
- 44
- Median AQI
- 68.1%
- Good-air days
- 0
- Unhealthy days
- 28%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Edgefield County's air is good on balance, more polluted than the median US county, a median AQI of 44 with 68.1% of 273 monitored days in the Good band, driven mainly by PM2.5.
- 44
- median AQI · Good
- 68.1%
- days rated Good
- PM2.5
- main pollutant
- 28%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 98.
Data updated July 2026
- Good · 186 d · 68.1%
- Moderate · 87 d · 31.9%
How did Edgefield County's air break down in 2025?
Across 273 monitored days, 186 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 98 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 273 days monitored. Median AQI: 44 (Good).
Insights: Edgefield County, South Carolina. EPA monitors recorded a median Air Quality Index of 44 across 273 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 186 (68%) fell in the Good band (AQI 0–50), 87 (32%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 58, while the worst single-day peak hit 98 (Moderate). Residents averaged about 20.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (178 days), Ozone (95 days). Across the 2020–2025 trend window, good days shifted by -121 and the median AQI moved +7 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 98, moderate but never Unhealthy. Nearby counties show comparable readings: Aiken (89.1% good, AQI 39); Anderson (90.0% good, AQI 41); Berkeley (92.2% good, AQI 36); Charleston (59.0% good, AQI 47); Chesterfield (61.2% good, AQI 46); Darlington (87.3% good, AQI 42).
Air Quality Summary
Good Days
68.1%
186 of 273 monitored days
-6.9pp vs 75% target
Max AQI Recorded
98
Moderate
Health Grade
Moderate
90th-pct AQI 58
Edgefield County, Good days share 68.1%
National avg
Share of monitored days at AQI 0-50 (Good band).
Edgefield 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 273 monitored days across EPA AQI categories.
Good
186
68%
Moderate
87
32%
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 Edgefield County.
- PM2.5 · 178 days · 65.2%
- Ozone · 95 days · 34.8%
Health Impact Assessment
Moderate
Edgefield County's air quality is rated Moderate based on 68.1% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 68.1% of monitored days in 2025, with a median AQI of 44. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 178 of 273 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Edgefield County. Best year: 2020 (307 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 307 | 58 | 1 | 0 | 37 | 115 |
| 2021 | 261 | 93 | 0 | 0 | 39 | 87 |
| 2022 | 250 | 114 | 0 | 0 | 43 | 74 |
| 2023 | 217 | 148 | 0 | 0 | 44 | 96 |
| 2024 | 231 | 134 | 0 | 0 | 44 | 98 |
| 2025 | 186 | 87 | 0 | 0 | 44 | 98 |
How does Edgefield County compare?
How Edgefield County compares
Good-day share worse than US avg
Edgefield County 68.1%
Aiken County, South Carolina 89.1%
US average 76.5%
Median AQI worse than US avg
Edgefield County 44
Aiken County, South Carolina 39
US average 38
Unhealthy days / yr about average
Edgefield County 0
Aiken County, South Carolina 0
US average 0
Other Counties in South Carolina
Air quality comparison for nearby counties in South Carolina.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Edgefield County.
Baltimore County, Maryland
AQI 44 · 70.4% good
Baltimore (City) County, Maryland
AQI 44 · 68.7% good
Bartholomew County, Indiana
AQI 44 · 69.2% good
Berks County, Pennsylvania
AQI 44 · 65.6% good
Bolivar County, Mississippi
AQI 44 · 70.3% good
Brewster County, Texas
AQI 44 · 69.0% good
What Edgefield 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 44 means for exposure. Health guidance
- See how Edgefield County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Edgefield County with its South Carolina neighbours before drawing a conclusion about the region. All of South Carolina
Based on 273 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 Edgefield County, South Carolina? ▼
Edgefield County has a median Air Quality Index (AQI) of 44, rated "Good." 68.1% of monitored days (186 out of 273) had good air quality in 2025.
What is the main pollutant in Edgefield County? ▼
The primary pollutant in Edgefield County is Fine Particles (PM2.5), which was the main AQI driver on 178 days (65% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Edgefield County have? ▼
In 2025, Edgefield County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 98.
Is the air quality in Edgefield County getting better or worse? ▼
Air quality in Edgefield County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 307 good days. Worst year: 2025 with 186 good days.
What does AQI 44 mean for health? ▼
Edgefield County's median AQI of 44 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 Edgefield County compare to other counties in South Carolina? ▼
Edgefield County has 68.1% good air days. Nearby counties in South Carolina: Aiken (89.1% good), Anderson (90.0% good), Berkeley (92.2% good), Charleston (59.0% good), Chesterfield (61.2% good), Darlington (87.3% good).
What is the 90th percentile AQI in Edgefield County? ▼
The 90th percentile AQI for Edgefield County is 58, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 98 (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.