Charleston, SC Air Quality in July

Across 2019–2025, Charleston's July air quality had a median AQI of 45 (Good) over 217 monitored days in the Charleston-North Charleston, SC area. 0.0% of July days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 86.6% of days. The cleanest July on record here was 2022 (median AQI 39, 0 days above 100) and the worst was 2023 (median 52, 0 days above 100, peak AQI 93).

45
Median AQI
Good
0.0%
Days above AQI 100
0 of 217 days
59
90th percentile AQI
worst 1 day in 10
93
Peak AQI
Moderate
PM2.5
Main pollutant
86.6% of days
62.7%
Good days
136 of 217
  • Good: 62.7%
  • Moderate: 37.3%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

Reduce Indoor Ozone in Charleston

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QUICK ANSWER

How is the air in Charleston in July?

Good on a typical day: median AQI 45 across 2019–2025, with 0.0% of July days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 62.7% of July days were Good (AQI 0–50), 37.3% Moderate (51–100).
  • 0 days of 217 reached AQI 101+; the July peak was 93.
  • Best July: 2022; worst July: 2023.

Frequently asked questions

What is the air quality like in Charleston in July?

Across 2019–2025, the median daily AQI in Charleston in July was 45 (Good). 62.7% of days were Good, 37.3% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.

Is July a good time for outdoor exercise in Charleston?

A typical July day in Charleston sits in the Good range (median AQI 45), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of July days reached AQI 101+ in 2019–2025.

Which pollutant causes Charleston's July air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 86.6% of July days in Charleston. The highest July AQI recorded in 2019–2025 was 93 (Moderate), in 2023.

Charleston July air quality, year by year

Charleston July air quality by year (Charleston-North Charleston, SC, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193144076PM2.5
20203147068PM2.5
20213144077PM2.5
2022cleanest3139060PM2.5
2023worst3152093PM2.5
20243142061PM2.5
20253145056PM2.5

What July air means in Charleston

A typical July day in Charleston sits in the Good range (median AQI 45), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of July days reached AQI 101+ in 2019–2025.

July's median AQI of 45 is in line with Charleston's whole-year median of 47, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median July AQI across every EPA metro area (103,858 metro-days, 2019–2025) is 47, so Charleston runs in line with the national July norm; 0.0% of its July days topped AQI 100 versus 3.6% nationally (below average).

July is part of Charleston's summer season (June, July, August); the summer page pools all three months.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Charleston

The latest EPA AirNow observation puts Charleston's AQI at 31 (O3). The figures above are multi-year month statistics, not today's reading.

View current Charleston air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Charleston-North Charleston, SC), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.