North Carolina · County air quality · 2025

Catawba County, North Carolina

Median AQI 42 (Good). 68.9% of monitored days rated Good, direct from EPA Air Quality System stations.

42
Median AQI
68.9%
Good-air days
0
Unhealthy days
30%
Cleaner than US counties

Catawba County's 2025 annual median AQI is 42 (Good), with 68.9% Good days

According to the U.S. EPA Air Quality System, Catawba County, North Carolina posted a 2025 median AQI of 42 (Good) across 347 monitored days, with 68.9% 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
Catawba County's 68.9% Good-day share places it cleaner than 30% of US counties in 2025.
Closest median-AQI peer
Ada County (74.0% Good, median AQI 42) is the closest nationwide median-AQI peer to Catawba County.
2020–2025 trend
Catawba County's floor-qualifying Good-day share is stable from 2020 to 2025 (69.2% → 68.9%).
Median AQI
Median AQI: 42

According to the 2025 EPA AQS county release on PlainAirData, Catawba County, North Carolina ranks #581 of 951 by median AQI (42) and #667 by good-day share (68.9%). 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
  • Catawba County's Good-day share rose from 66.3% to 68.9% between the 2024 and 2025 EPA annual releases, a change of +2.6 percentage points.

Compared against 350 monitored days in 2024 and 347 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

Catawba 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 347 monitored days G M Median AQI 42 0 50 100 150 200 300 500 Catawba County
  • Good · 239 d · 68.9%
  • Moderate · 108 d · 31.1%

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

Across 347 monitored days, 239 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 88 (Moderate).

EPA AQS →
Catawba County, Good days share 68.9%
National avg

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

Catawba 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 Catawba County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Catawba County's Good-day share is 68.9% - cleaner than 30% of that comparison set.

Catawba County Good-day share vs. every US county

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

68.9% 30th percentile higher than 30% 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%). This entry sits in this band. 70.0%–75.0%: 109 US counties (11%). Above this entry. 75.0%–80.0%: 114 US counties (12%). Above this entry. 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 Catawba County.

Catawba County, North Carolina 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% Catawba County, North Carolina · 347 monitored days Criteria pollutant column
  • PM2.5 · 347 days · 100.0%

2024 daily-monitor rhythm in Catawba County

Month-by-month median AQI from EPA day-level county monitors (350 reported days in 2024). Aug posted the highest typical readings (median AQI 51, peak 68); May was cleanest at median 34. Summer months (Jun–Aug) averaged median AQI 48 vs 41 in Dec–Feb.

0 10 20 30 40 50 60 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 34 49 43 43 34 48 44 51 35 47 39 41
Catawba County median daily AQI by calendar month (2024, EPA daily county file)

Five-year seasonal record

EPA day-level county files · 2020–2024

1,753 daily readings show a recurring local pattern: Jun has the highest matched-month median AQI (49), while Sep is lowest (37). Each cell is that month’s median daily AQI, not a current-air forecast.

JanFebMarAprMayJunJulAugSepOctNovDec
2020 373644333742424435465352
2021 383143525846545444394051
2022 514539464152424331323448
2023 354245454958524239364444
2024 344943433448445135473941

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

Moderate

Catawba County's air quality is rated Moderate based on 68.9% good air days. No unhealthy air days were recorded in 2025.

Air quality was acceptable on 68.9% of monitored days in 2025, with a median AQI of 42. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.

The dominant pollutant is PM2.5, driving AQI on 347 of 347 monitored days.

5-Year Air Quality Trend

Air quality is stable in Catawba County. Highest Good-day share: 2020 (69.2%, 247 of 357 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2020 247 110 0 0 42
2021 197 147 0 0 46
2022 234 121 0 0 44
2023 212 132 3 0 43
2024 232 118 0 0 42
2025 239 108 0 0 42

How does Catawba County compare?

How Catawba County compares

Good-day share worse than typical
Catawba County 68.9%
Ada County, Idaho 74.0%
Typical US county 76.0%
Median AQI worse than typical
Catawba County 42
Ada County, Idaho 42
Typical US county 39
Unhealthy days / yr better than typical
Catawba County 0
Ada County, Idaho 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 Catawba County, North Carolina · 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.