Median AQI
46
Good
Mississippi · County air quality · 2025
Forrest County, Mississippi
Median AQI 46 (Good). 62.4% of monitored days rated Good, direct from EPA Air Quality System stations.
- 46
- Median AQI
- 62.4%
- Good-air days
- 0
- Unhealthy days
- 19%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Forrest County's air is good on balance, among the more polluted 10% of US counties, a median AQI of 46 with 62.4% of 271 monitored days in the Good band, driven mainly by PM2.5.
- 46
- median AQI · Good
- 62.4%
- days rated Good
- PM2.5
- main pollutant
- 19%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 97.
Data updated July 2026
- Good · 169 d · 62.4%
- Moderate · 102 d · 37.6%
How did Forrest County's air break down in 2025?
Across 271 monitored days, 169 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). 271 days monitored. Median AQI: 46 (Good).
Insights: Forrest County, Mississippi. EPA monitors recorded a median Air Quality Index of 46 across 271 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 169 (62%) fell in the Good band (AQI 0–50), 102 (38%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 59, while the worst single-day peak hit 97 (Moderate). Residents averaged about 18.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (271 days). Across the 2020–2025 trend window, good days shifted by -27 and the median AQI moved -2 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 97, moderate but never Unhealthy. Nearby counties show comparable readings: Bolivar (70.3% good, AQI 44); DeSoto (67.0% good, AQI 44); Hancock (67.8% good, AQI 44); Harrison (64.5% good, AQI 45); Hinds (43.4% good, AQI 52); Jackson (65.2% good, AQI 46).
Air Quality Summary
Good Days
62.4%
169 of 271 monitored days
-12.6pp vs 75% target
Max AQI Recorded
97
Moderate
Health Grade
Moderate
90th-pct AQI 59
Forrest County, Good days share 62.4%
National avg
Share of monitored days at AQI 0-50 (Good band).
Forrest 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 271 monitored days across EPA AQI categories.
Good
169
62%
Moderate
102
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 Forrest County.
- PM2.5 · 271 days · 100.0%
Health Impact Assessment
Moderate
Forrest County's air quality is rated Moderate based on 62.4% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 62.4% 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 271 of 271 monitored days.
5-Year Air Quality Trend
Air quality is improving in Forrest County. Best year: 2024 (202 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 196 | 165 | 0 | 0 | 48 | 97 |
| 2021 | 178 | 185 | 0 | 0 | 51 | 93 |
| 2022 | 178 | 186 | 1 | 0 | 51 | 105 |
| 2023 | 145 | 220 | 0 | 0 | 53 | 94 |
| 2024 | 202 | 159 | 1 | 0 | 47 | 103 |
| 2025 | 169 | 102 | 0 | 0 | 46 | 97 |
How does Forrest County compare?
How Forrest County compares
Good-day share worse than US avg
Forrest County 62.4%
Bolivar County, Mississippi 70.3%
US average 76.5%
Median AQI worse than US avg
Forrest County 46
Bolivar County, Mississippi 44
US average 38
Unhealthy days / yr about average
Forrest County 0
Bolivar County, Mississippi 0
US average 0
Other Counties in Mississippi
Air quality comparison for nearby counties in Mississippi.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Forrest 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 Forrest 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 Forrest County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Forrest County with its Mississippi neighbours before drawing a conclusion about the region. All of Mississippi
Based on 271 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 Forrest County, Mississippi? ▼
Forrest County has a median Air Quality Index (AQI) of 46, rated "Good." 62.4% of monitored days (169 out of 271) had good air quality in 2025.
What is the main pollutant in Forrest County? ▼
The primary pollutant in Forrest County is Fine Particles (PM2.5), which was the main AQI driver on 271 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Forrest County have? ▼
In 2025, Forrest County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 97.
Is the air quality in Forrest County getting better or worse? ▼
Air quality in Forrest County is improving based on 5-year trends (2020-2025). Best year: 2024 with 202 good days. Worst year: 2023 with 145 good days.
What does AQI 46 mean for health? ▼
Forrest 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 Forrest County compare to other counties in Mississippi? ▼
Forrest County has 62.4% good air days. Nearby counties in Mississippi: Bolivar (70.3% good), DeSoto (67.0% good), Hancock (67.8% good), Harrison (64.5% good), Hinds (43.4% good), Jackson (65.2% good).
What is the 90th percentile AQI in Forrest County? ▼
The 90th percentile AQI for Forrest County is 59, 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.