Median AQI
42
Good
Virginia · County air quality · 2025
Chesterfield County, Virginia
Median AQI 42 (Good). 77.2% of monitored days rated Good, direct from EPA Air Quality System stations.
- 42
- Median AQI
- 77.2%
- Good-air days
- 0
- Unhealthy days
- 44%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Chesterfield County's air is good on balance, more polluted than the median US county, a median AQI of 42 with 77.2% of 272 monitored days in the Good band, driven mainly by PM2.5.
- 42
- median AQI · Good
- 77.2%
- days rated Good
- PM2.5
- main pollutant
- 44%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 80.
Data updated July 2026
- Good · 210 d · 77.2%
- Moderate · 62 d · 22.8%
How did Chesterfield County's air break down in 2025?
Across 272 monitored days, 210 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 80 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 272 days monitored. Median AQI: 42 (Good).
Insights: Chesterfield County, Virginia. EPA monitors recorded a median Air Quality Index of 42 across 272 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 210 (77%) fell in the Good band (AQI 0–50), 62 (23%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 56, while the worst single-day peak hit 80 (Moderate). Residents averaged about 23.2 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (162 days), Ozone (110 days). Across the 2020–2025 trend window, good days shifted by -55 and the median AQI moved +8 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 80, moderate but never Unhealthy. Nearby counties show comparable readings: Albemarle (77.9% good, AQI 41); Arlington (84.8% good, AQI 40); Bristol City (78.3% good, AQI 33); Caroline (96.2% good, AQI 37); Carroll (100.0% good, AQI 9); Charles (88.6% good, AQI 38).
Air Quality Summary
Good Days
77.2%
210 of 272 monitored days
2.2pp vs 75% target
Max AQI Recorded
80
Moderate
Health Grade
Good
90th-pct AQI 56
Chesterfield County, Good days share 77.2%
National avg
Share of monitored days at AQI 0-50 (Good band).
Chesterfield 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 272 monitored days across EPA AQI categories.
Good
210
77%
Moderate
62
23%
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 Chesterfield County.
- PM2.5 · 162 days · 59.6%
- Ozone · 110 days · 40.4%
Health Impact Assessment
Good
Chesterfield County's air quality is rated Good based on 77.2% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 77.2% of monitored days in 2025, with a median AQI of 42. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 162 of 272 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Chesterfield County. Best year: 2024 (273 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 265 | 14 | 0 | 0 | 34 | 61 |
| 2021 | 243 | 39 | 1 | 0 | 38 | 101 |
| 2022 | 264 | 22 | 0 | 0 | 38 | 80 |
| 2023 | 242 | 35 | 1 | 0 | 41 | 139 |
| 2024 | 273 | 88 | 0 | 0 | 41 | 77 |
| 2025 | 210 | 62 | 0 | 0 | 42 | 80 |
How does Chesterfield County compare?
How Chesterfield County compares
Good-day share better than US avg
Chesterfield County 77.2%
Albemarle County, Virginia 77.9%
US average 76.5%
Median AQI worse than US avg
Chesterfield County 42
Albemarle County, Virginia 41
US average 38
Unhealthy days / yr about average
Chesterfield County 0
Albemarle County, Virginia 0
US average 0
Other Counties in Virginia
Air quality comparison for nearby counties in Virginia.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Chesterfield County.
Adams County, Pennsylvania
AQI 42 · 73.8% good
Anderson County, Tennessee
AQI 42 · 91.0% good
Andrew County, Missouri
AQI 42 · 84.3% good
Armstrong County, Pennsylvania
AQI 42 · 68.1% good
Baldwin County, Alabama
AQI 42 · 72.2% good
Belmont County, Ohio
AQI 42 · 63.0% good
What Chesterfield 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 42 means for exposure. Health guidance
- See how Chesterfield County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Chesterfield County with its Virginia neighbours before drawing a conclusion about the region. All of Virginia
Based on 272 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 Chesterfield County, Virginia? ▼
Chesterfield County has a median Air Quality Index (AQI) of 42, rated "Good." 77.2% of monitored days (210 out of 272) had good air quality in 2025.
What is the main pollutant in Chesterfield County? ▼
The primary pollutant in Chesterfield County is Fine Particles (PM2.5), which was the main AQI driver on 162 days (60% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Chesterfield County have? ▼
In 2025, Chesterfield County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 80.
Is the air quality in Chesterfield County getting better or worse? ▼
Air quality in Chesterfield County is worsening based on 5-year trends (2020-2025). Best year: 2024 with 273 good days. Worst year: 2025 with 210 good days.
What does AQI 42 mean for health? ▼
Chesterfield County's median AQI of 42 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 Chesterfield County compare to other counties in Virginia? ▼
Chesterfield County has 77.2% good air days. Nearby counties in Virginia: Albemarle (77.9% good), Arlington (84.8% good), Bristol City (78.3% good), Caroline (96.2% good), Carroll (100.0% good), Charles (88.6% good).
What is the 90th percentile AQI in Chesterfield County? ▼
The 90th percentile AQI for Chesterfield County is 56, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 80 (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.