Ohio · County air quality · 2025

Lorain County, Ohio

Median AQI 39 (Good). 87.3% of monitored days rated Good, direct from EPA Air Quality System stations.

39
Median AQI
87.3%
Good-air days
0
Unhealthy days
75%
Cleaner than US counties

Lorain County's 2025 annual median AQI is 39 (Good), with 87.3% Good days

According to the U.S. EPA Air Quality System, Lorain County, Ohio posted a 2025 median AQI of 39 (Good) across 237 monitored days, with 87.3% 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
Lorain County's 87.3% Good-day share places it cleaner than 75% of US counties in 2025.
Closest median-AQI peer
Aiken County (90.6% Good, median AQI 39) is the closest nationwide median-AQI peer to Lorain County.
2020–2025 trend
Lorain County's floor-qualifying Good-day share is improving from 2020 to 2025 (80.7% → 87.3%).
Median AQI
Median AQI: 39

According to the 2025 EPA AQS county release on PlainAirData, Lorain County, Ohio ranks #392 of 951 by median AQI (39) and #240 by good-day share (87.3%). 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
  • Lorain County's peak single-day AQI rose from 74 to 119 between the 2024 and 2025 EPA annual releases, a change of +45 points.

Compared against 245 monitored days in 2024 and 237 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

Lorain 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 237 monitored days G M Median AQI 39 0 50 100 150 200 300 500 Lorain County
  • Good · 207 d · 87.3%
  • Moderate · 29 d · 12.2%
  • USG · 1 d · 0.4%

How did Lorain County's air break down in 2025?

Across 237 monitored days, 207 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 119 (USG).

EPA AQS →
Lorain County, Good days share 87.3%
National avg

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

Lorain 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 Lorain County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Lorain County's Good-day share is 87.3% - cleaner than 75% of that comparison set.

Lorain County Good-day share vs. every US county

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

87.3% Cleaner than 75% higher than 75% 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%). Below this entry. 80.0%–85.0%: 123 US counties (13%). Below this entry. 85.0%–90.0%: 99 US counties (10%). This entry sits in this band. 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 Lorain County.

Lorain County, Ohio 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. Ozone · 100.0% 0% 25% 50% 75% 100% Lorain County, Ohio · 237 monitored days Criteria pollutant column
  • Ozone · 237 days · 100.0%

2024 daily-monitor rhythm in Lorain County

Month-by-month median AQI from EPA day-level county monitors (245 reported days in 2024). Jul posted the highest typical readings (median AQI 44, peak 67); Oct was cleanest at median 33.

0 10 20 30 40 50 Mar Apr May Jun Jul Aug Sep Oct 35 40 41 42 44 39 40 33
Lorain County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,393 daily readings show a recurring local pattern: Feb has the highest matched-month median AQI (45), while Oct is lowest (30). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 313840403944483935303041
2021 46523942374342473829--
2022 --3534374239353031--
2023 --3640414239383128--
2024 --3540414244394033--

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

Lorain County's air quality is rated Good based on 87.3% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 87.3% of monitored days in 2025, with a median AQI of 39. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is Ozone, driving AQI on 237 of 237 monitored days.

5-Year Air Quality Trend

Air quality is improving in Lorain County. Highest Good-day share: 2022 (93.8%, 228 of 243 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 289 68 0 1 39
2021 208 96 0 0 41
2022 228 14 1 0 35
2023 221 22 0 0 37
2024 216 29 0 0 39
2025 207 29 1 0 39

How does Lorain County compare?

How Lorain County compares

Good-day share better than typical
Lorain County 87.3%
Aiken County, South Carolina 90.6%
Typical US county 76.0%
Median AQI about typical
Lorain County 39
Aiken County, South Carolina 39
Typical US county 39
Unhealthy days / yr better than typical
Lorain County 0
Aiken County, South Carolina 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 Lorain County, Ohio · 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.