Virginia · County air quality · 2025

Salem City County, Virginia

Median AQI 31 (Good). 79.7% of monitored days rated Good, direct from EPA Air Quality System stations.

31
Median AQI
79.7%
Good-air days
0
Unhealthy days
55%
Cleaner than US counties

Salem City County's 2025 annual median AQI is 31 (Good), with 79.7% Good days

According to the U.S. EPA Air Quality System, Salem City County, Virginia posted a 2025 median AQI of 31 (Good) across 113 monitored days, with 79.7% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US
Salem City County's 79.7% Good-day share places it cleaner than 55% of US counties in 2025.
Closest median-AQI peer
Athens County (83.4% Good, median AQI 31) is the closest nationwide median-AQI peer to Salem City County.
2020–2025 trend
Salem City County's floor-qualifying Good-day share is worsening from 2020 to 2025 (85.5% → 79.6%).
Median AQI
Median AQI: 31

According to the 2025 EPA AQS county release on PlainAirData, Salem City County, Virginia ranks #100 of 951 by median AQI (31) and #425 by good-day share (79.7%). Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ largest of 7 at 100.0% Good days #1 by good-day share (100.0%, median AQI 9) at median-AQI #7.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Salem City County's Good-day share fell from 83.2% to 79.6% between the 2024 and 2025 EPA annual releases, a change of -3.5 percentage points.

Compared against 119 monitored days in 2024 and 113 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Data updated August 2026

Salem City County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 113 monitored days G M Median AQI 31 0 50 100 150 200 300 500 Salem City County
  • Good · 90 d · 79.6%
  • Moderate · 23 d · 20.4%

How did Salem City County's air break down in 2025?

Across 113 monitored days, 90 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 76 (Moderate).

EPA AQS →
Salem City County, Good days share 79.7%
National avg

Share of monitored days at AQI 0-50 (Good band).

Salem City 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).

Where Salem City County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Salem City County's Good-day share is 79.7% - cleaner than 55% of that comparison set.

Salem City County Good-day share vs. every US county

Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

79.7% Cleaner than 55% higher than 55% of 951 US counties

0.0%–5.0%: 0 US counties (0%). Below this entry. 5.0%–10.0%: 1 US counties (0%). Below this entry. 10.0%–15.0%: 4 US counties (0%). Below this entry. 15.0%–20.0%: 4 US counties (0%). Below this entry. 20.0%–25.0%: 1 US counties (0%). Below this entry. 25.0%–30.0%: 5 US counties (1%). Below this entry. 30.0%–35.0%: 9 US counties (1%). Below this entry. 35.0%–40.0%: 4 US counties (0%). Below this entry. 40.0%–45.0%: 16 US counties (2%). Below this entry. 45.0%–50.0%: 16 US counties (2%). Below this entry. 50.0%–55.0%: 32 US counties (3%). Below this entry. 55.0%–60.0%: 50 US counties (5%). Below this entry. 60.0%–65.0%: 77 US counties (8%). Below this entry. 65.0%–70.0%: 93 US counties (10%). Below this entry. 70.0%–75.0%: 109 US counties (11%). Below this entry. 75.0%–80.0%: 114 US counties (12%). This entry sits in this band. 80.0%–85.0%: 123 US counties (13%). Above this entry. 85.0%–90.0%: 99 US counties (10%). Above this entry. 90.0%–95.0%: 117 US counties (12%). Above this entry. 95.0%–100.0%: 70 US counties (7%). Above this entry. 100.0%–105.0%: 7 US counties (1%). Above this entry. This county 0.0% 100% every floor-qualified US county, bucketed by value

Each bar is a band; taller bars hold more US counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Pollutant Breakdown

Days where each pollutant was the primary driver of AQI readings in Salem City County.

Salem City County, Virginia criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. PM2.5 · 100.0% 0% 25% 50% 75% 100% Salem City County, Virginia · 113 monitored days Criteria pollutant column
  • PM2.5 · 113 days · 100.0%

2024 daily-monitor rhythm in Salem City County

Month-by-month median AQI from EPA day-level county monitors (119 reported days in 2024). Jun posted the highest typical readings (median AQI 47, peak 58); Jan was cleanest at median 20. Summer months (Jun–Aug) averaged median AQI 44 vs 25 in Dec–Feb.

0 10 20 30 40 50 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 20 33 27 42 28 47 43 42 25 31 26 22
Salem City County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

590 daily readings show a recurring local pattern: Jul has the highest matched-month median AQI (48), while Mar is lowest (26). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 362417212238513832333829
2021 323524353935515134313038
2022 332932303051443727292829
2023 253332324459503841333634
2024 203327422847434225312622

Lower AQI is better. The colors summarize EPA AQI bands; gaps mean the county had no day-level record for that month.

Health Impact Assessment

Good

Salem City County's air quality is rated Good based on 79.7% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 79.7% of monitored days in 2025, with a median AQI of 31. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is PM2.5, driving AQI on 113 of 113 monitored days.

5-Year Air Quality Trend

Air quality is worsening in Salem City County. Highest Good-day share: 2020 (85.5%, 94 of 110 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 94 16 0 0 31
2021 95 25 0 0 35
2022 98 23 0 0 33
2023 87 32 1 0 36
2024 99 20 0 0 32
2025 90 23 0 0 31

How does Salem City County compare?

How Salem City County compares

Good-day share better than typical
Salem City County 79.7%
Athens County, Ohio 83.4%
Typical US county 76.0%
Median AQI better than typical
Salem City County 31
Athens County, Ohio 31
Typical US county 39
Unhealthy days / yr better than typical
Salem City County 0
Athens County, Ohio 0
Typical US county 1

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. Spotted a figure that looks wrong? Report a correction.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Salem City County, Virginia · 2020–2025

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Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.

Every figure on PlainAirData 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.