Metro area air quality · 2025

Hanford-Corcoran, CA

Median AQI 57 (Moderate). 34.5% of monitored days rated Good across this metro's EPA monitoring network.

Compiled by PlainAirData · August 23, 2026

57
Median AQI: 34.5%
Good-air days: 0
Unhealthy days: 4%
Cleaner than US metros

Hanford-Corcoran, CA posted a 2025 median AQI of 57 (Moderate) with 34.5% Good days

According to the U.S. EPA Air Quality System, the Hanford-Corcoran, CA CBSA recorded a median AQI of 57 across 365 monitored days in 2025, with 34.5% 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 Hanford-Corcoran, CA CBSA's 34.5% Good-day share places it cleaner than 4% of US metros in 2025.
Closest median-AQI peer: Brownsville-Harlingen, TX (29.9% Good, median AQI 57) is the closest nationwide median-AQI peer to Hanford-Corcoran, CA.
2020–2025 Good-day shift: Hanford-Corcoran, CA's Good-day share moved +11.0 points from 2020 to 2025 (median AQI -13).
Median AQI: Median AQI: 57

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

The verdict

The Hanford-Corcoran, CA metro runs moderate on the EPA scale, among the more polluted US metros, a median AQI of 57 with 34.5% of 365 monitored days in the Good band.

57
median AQI · Moderate: 34.5%
days rated Good: 4%
cleaner than US metros: 133
worst single reading

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

Hanford-Corcoran, CA metro's Good-day share rose from 30.0% to 35.6% between the 2024 and 2025 EPA annual releases, a change of +5.6 percentage points.
Hanford-Corcoran, CA metro's peak single-day AQI fell from 156 to 133 between the 2024 and 2025 EPA annual releases, a change of -23 points.
Hanford-Corcoran, CA metro's Unhealthy-category days fell from 2 to 0 between the 2024 and 2025 EPA annual releases, a change of -2 days.
Hanford-Corcoran, CA metro's median AQI fell from 60 to 57 between the 2024 and 2025 EPA annual releases, a change of -3 points.

Insights: Hanford-Corcoran, CA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 57 over 365 measured days in 2025, which corresponds to a Moderate band and a Poor metro-wide health grade. The monitored-day split lands at 126 Good days (35%), 228 Moderate (62%), and 11 Unhealthy-for-Sensitive-Groups (3%). The 90th-percentile AQI finished at 85 while the highest single-day reading hit 133 (USG). Metro residents averaged roughly 10.4 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 +11.0 points (measured against 309 monitored days in 2020 and 354 in 2025, so raw day counts are not comparable) and the median AQI moved -13 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 Brownsville-Harlingen, TX (29.9% good, AQI 57); Salt Lake City, UT (32.9% good, AQI 57); Chicago-Naperville-Elgin, IL-IN-WI (29.9% good, AQI 56).

Air Quality Summary

Median AQI

Moderate

Good Days

34.5%

126 of 365 days

Max AQI

133

USG

Health Grade

Poor

90th pct: 85

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

126

35%

Moderate

228

62%

USG

Unhealthy

Very Unhealthy

Hazardous

Health Impact Assessment

Poor

The Hanford-Corcoran, CA metro area's air quality is rated Poor based on 34.5% 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 Hanford-Corcoran, CA metro compare?

How Hanford-Corcoran, CA compares

Compare against

Good-day share worse than typical

Hanford-Corcoran, CA 34.5%

Brownsville-Harlingen, TX 29.9%

Typical US metro 70.6%

Median AQI worse than typical

Hanford-Corcoran, CA 57

Brownsville-Harlingen, TX 57

Typical US metro 41

Unhealthy days / yr better than typical

Hanford-Corcoran, CA 0

Brownsville-Harlingen, TX 0

Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Hanford-Corcoran, CA metro. Highest Good-day share: 2023 (36.8%, 124 of 337 monitored days).

Year	Good	Moderate	Unhealthy	Median AQI	Max AQI
2020	76	220	13	70	548
2021	84	230	10	64	685
2022	71	244	2	69	187
2023	124	213	0	58	148
2024	100	231	2	60	156
2025	126	228	0	57	133

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Hanford-Corcoran, CA (57).

Brownsville-Harlingen, TX

Median AQI 57 · 29.9% Good-day share

Salt Lake City, UT

Median AQI 57 · 32.9% Good-day share

Chicago-Naperville-Elgin, IL-IN-WI

Median AQI 56 · 29.9% Good-day share

Cincinnati, OH-KY-IN

Median AQI 56 · 26.0% Good-day share

Denver-Aurora-Lakewood, CO

Median AQI 58 · 28.8% Good-day share

St. Louis, MO-IL

Median AQI 56 · 31.2% Good-day share

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Hanford-Corcoran, CA's 0 (independent of median AQI).

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

More Air Quality Data

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

Cleanest Metro Areas

U.S. metros ranked by their share of Good air-quality days.

Worst Air Quality

Counties and metros with the most unhealthy air days.

All Metro Areas

Annual AQI by CBSA for every monitored U.S. metro area.

Best and Worst City Air

What drives urban air quality and how metro areas compare.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the Hanford-Corcoran, CA metro area? ▼

The Hanford-Corcoran, CA metro area has a median Air Quality Index (AQI) of 57, rated "Moderate." 34.5% of monitored days (126 out of 365) had good air quality in 2025.

How many unhealthy air days does Hanford-Corcoran, CA have? ▼

In 2025, the Hanford-Corcoran, CA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 133.

Is air quality in Hanford-Corcoran, CA getting better or worse? ▼

Air quality in the Hanford-Corcoran, CA 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: 2023 at 36.8% (124 of 337 days). Lowest qualifying Good-day share: 2022 at 22.4% (71 of 317 days).

What does AQI 57 mean for health? ▼

An AQI of 57 is "Moderate", air quality is acceptable, but some pollutants may pose a moderate health concern for a small number of sensitive individuals.

What is the 90th percentile AQI for Hanford-Corcoran, CA? ▼

The 90th percentile AQI for the Hanford-Corcoran, CA metro area is 85, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 133 (USG).

How does Hanford-Corcoran, CA compare to other metro areas? ▼

The Hanford-Corcoran, CA metro has 34.5% good air days. Similar metros: Brownsville-Harlingen, TX (29.9% good), Salt Lake City, UT (32.9% good), Chicago-Naperville-Elgin, IL-IN-WI (29.9% 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.

Read our methodology , how this data is sourced, computed, and verified.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025 Accessed 2026-07-06

Send the source-year summary or download its ready-to-use data card.

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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.