Metro area air quality · 2025

Allentown-Bethlehem-Easton, PA-NJ

Median AQI 42 (Good). 66.8% of monitored days rated Good across this metro's EPA monitoring network.

42
Median AQI
66.8%
Good-air days
0
Unhealthy days
38%
Cleaner than US metros

Allentown-Bethlehem-Easton, PA-NJ posted a 2025 median AQI of 42 (Good) with 66.8% Good days

According to the U.S. EPA Air Quality System, the Allentown-Bethlehem-Easton, PA-NJ CBSA recorded a median AQI of 42 across 365 monitored days in 2025, with 66.8% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US metros
The Allentown-Bethlehem-Easton, PA-NJ CBSA's 66.8% Good-day share places it cleaner than 38% of US metros in 2025.
Closest median-AQI peer
Amarillo, TX (78.4% Good, median AQI 42) is the closest nationwide median-AQI peer to Allentown-Bethlehem-Easton, PA-NJ.
2020–2025 Good-day shift
Allentown-Bethlehem-Easton, PA-NJ's Good-day share moved +3.3 points from 2020 to 2025 (median AQI -2).
Median AQI
Median AQI: 42

Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →

The verdict

The Allentown-Bethlehem-Easton, PA-NJ metro runs good on the EPA scale, more polluted than the median US metro, a median AQI of 42 with 66.8% of 365 monitored days in the Good band.

42
median AQI · Good
66.8%
days rated Good
38%
cleaner than US metros
122
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Allentown-Bethlehem-Easton, PA-NJ metro's Good-day share fell from 69.1% to 67.4% between the 2024 and 2025 EPA annual releases, a change of -1.7 percentage points.

Compared against 362 monitored days in 2024 and 362 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

Insights: Allentown-Bethlehem-Easton, PA-NJ metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 42 over 365 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 244 Good days (67%), 118 Moderate (32%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 67 while the highest single-day reading hit 122 (USG). Metro residents averaged roughly 20.1 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +3.3 points and the median AQI moved -2 points, which classifies the multi-year trajectory as improving. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Amarillo, TX (78.4% good, AQI 42); Carson City, NV (86.2% good, AQI 42); Casper, WY (86.3% good, AQI 42).

Air Quality Summary

Median AQI

42

Good

Good Days

66.8%

244 of 365 days

Max AQI

122

USG

Health Grade

Moderate

90th pct: 67

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

244

67%

Moderate

118

32%

USG

3

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Allentown-Bethlehem-Easton, PA-NJ metro area's air quality is rated Moderate based on 66.8% good air days. No unhealthy air days were recorded in 2025.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Allentown-Bethlehem-Easton, PA-NJ metro compare?

How Allentown-Bethlehem-Easton, PA-NJ compares

Good-day share worse than typical
Allentown-Bethlehem-Easton, PA-NJ 66.8%
Amarillo, TX 78.4%
Typical US metro 70.6%
Median AQI worse than typical
Allentown-Bethlehem-Easton, PA-NJ 42
Amarillo, TX 42
Typical US metro 41
Unhealthy days / yr better than typical
Allentown-Bethlehem-Easton, PA-NJ 0
Amarillo, TX 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Allentown-Bethlehem-Easton, PA-NJ metro. Highest Good-day share: 2024 (69.1%, 250 of 362 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 234 131 0 44
2021 182 179 1 51
2022 207 156 0 48
2023 194 164 4 48
2024 250 112 0 41
2025 244 118 0 42

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Allentown-Bethlehem-Easton, PA-NJ (42).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Allentown-Bethlehem-Easton, PA-NJ's 0 (independent of median AQI).

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Allentown-Bethlehem-Easton, PA-NJ metro area?
The Allentown-Bethlehem-Easton, PA-NJ metro area has a median Air Quality Index (AQI) of 42, rated "Good." 66.8% of monitored days (244 out of 365) had good air quality in 2025.
How many unhealthy air days does Allentown-Bethlehem-Easton, PA-NJ have?
In 2025, the Allentown-Bethlehem-Easton, PA-NJ metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 122.
Is air quality in Allentown-Bethlehem-Easton, PA-NJ getting better or worse?
Air quality in the Allentown-Bethlehem-Easton, PA-NJ metro is improving across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2024 at 69.1% (250 of 362 days). Lowest qualifying Good-day share: 2021 at 50.3% (182 of 362 days).
What does AQI 42 mean for health?
An AQI of 42 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
What is the 90th percentile AQI for Allentown-Bethlehem-Easton, PA-NJ?
The 90th percentile AQI for the Allentown-Bethlehem-Easton, PA-NJ metro area is 67, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 122 (USG).
How does Allentown-Bethlehem-Easton, PA-NJ compare to other metro areas?
The Allentown-Bethlehem-Easton, PA-NJ metro has 66.8% good air days. Similar metros: Amarillo, TX (78.4% good), Carson City, NV (86.2% good), Casper, WY (86.3% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025

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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.