Metro area air quality · 2025

Stockton-Lodi, CA

Median AQI 46 (Good). 60.0% of monitored days rated Good across this metro's EPA monitoring network.

46
Median AQI
60.0%
Good-air days
0
Unhealthy days
25%
Cleaner than US metros

Stockton-Lodi, CA posted a 2025 median AQI of 46 (Good) with 60.0% Good days

According to the U.S. EPA Air Quality System, the Stockton-Lodi, CA CBSA recorded a median AQI of 46 across 365 monitored days in 2025, with 60.0% 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 Stockton-Lodi, CA CBSA's 60.0% Good-day share places it cleaner than 25% of US metros in 2025.
Closest median-AQI peer
Albany, GA (57.3% Good, median AQI 46) is the closest nationwide median-AQI peer to Stockton-Lodi, CA.
2020–2025 Good-day shift
Stockton-Lodi, CA's Good-day share moved +13.4 points from 2020 to 2025 (median AQI -8).
Median AQI
Median AQI: 46

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

The verdict

The Stockton-Lodi, CA metro runs good on the EPA scale, more polluted than the median US metro, a median AQI of 46 with 60.0% of 365 monitored days in the Good band.

46
median AQI · Good
60.0%
days rated Good
25%
cleaner than US metros
93
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
  • Stockton-Lodi, CA metro's Good-day share rose from 50.1% to 60.0% between the 2024 and 2025 EPA annual releases, a change of +9.9 percentage points.
  • Stockton-Lodi, CA metro's peak single-day AQI fell from 140 to 93 between the 2024 and 2025 EPA annual releases, a change of -47 points.
  • Stockton-Lodi, CA metro's median AQI fell from 51 to 46 between the 2024 and 2025 EPA annual releases, a change of -5 points.

Compared against 355 monitored days in 2024 and 365 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: Stockton-Lodi, CA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 46 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 219 Good days (60%), 146 Moderate (40%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 67 while the highest single-day reading hit 93 (Moderate). Metro residents averaged roughly 18.0 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 +13.4 points and the median AQI moved -8 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 Albany, GA (57.3% good, AQI 46); Athens-Clarke County, GA (57.8% good, AQI 46); Brookings, SD (58.6% good, AQI 46).

Air Quality Summary

Median AQI

46

Good

Good Days

60.0%

219 of 365 days

Max AQI

93

Moderate

Health Grade

Moderate

90th pct: 67

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

219

60%

Moderate

146

40%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Stockton-Lodi, CA metro area's air quality is rated Moderate based on 60.0% 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 Stockton-Lodi, CA metro compare?

How Stockton-Lodi, CA compares

Good-day share worse than typical
Stockton-Lodi, CA 60.0%
Albany, GA 57.3%
Typical US metro 70.6%
Median AQI worse than typical
Stockton-Lodi, CA 46
Albany, GA 46
Typical US metro 41
Unhealthy days / yr better than typical
Stockton-Lodi, CA 0
Albany, GA 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Stockton-Lodi, CA metro. Highest Good-day share: 2025 (60.0%, 219 of 365 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 162 173 13 54
2021 140 209 1 55
2022 192 164 0 48
2023 208 148 0 47
2024 178 177 0 51
2025 219 146 0 46

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Stockton-Lodi, CA (46).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Stockton-Lodi, CA'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 Stockton-Lodi, CA metro area?
The Stockton-Lodi, CA metro area has a median Air Quality Index (AQI) of 46, rated "Good." 60.0% of monitored days (219 out of 365) had good air quality in 2025.
How many unhealthy air days does Stockton-Lodi, CA have?
In 2025, the Stockton-Lodi, CA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 93.
Is air quality in Stockton-Lodi, CA getting better or worse?
Air quality in the Stockton-Lodi, 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: 2025 at 60.0% (219 of 365 days). Lowest qualifying Good-day share: 2021 at 40.0% (140 of 350 days).
What does AQI 46 mean for health?
An AQI of 46 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 Stockton-Lodi, CA?
The 90th percentile AQI for the Stockton-Lodi, CA metro area is 67, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 93 (Moderate).
How does Stockton-Lodi, CA compare to other metro areas?
The Stockton-Lodi, CA metro has 60.0% good air days. Similar metros: Albany, GA (57.3% good), Athens-Clarke County, GA (57.8% good), Brookings, SD (58.6% 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.