Air quality in San Marcos
The US Air Quality Index (EPA) grades air from 0 to 500 using fine particles (PM2.5/PM10), ozone and nitrogen dioxide. 0-50 is Good, 51-100 Moderate, 101-150 Unhealthy for Sensitive Groups, and anything higher affects everyone.
PM2.5
14.9 µg/m³
WHO guideline 15
PM10
20 µg/m³
WHO guideline 45
Hour by hour (12h)
US EPA AQI
3:00 PM
💨
PM2.5 14.9 µg/m³
71Moderate
4:00 PM
💨
PM2.5 15.8 µg/m³
70Moderate
5:00 PM
💨
PM2.5 16.6 µg/m³
65Moderate
6:00 PM
💨
PM2.5 17.8 µg/m³
63Moderate
7:00 PM
💨
PM2.5 19.4 µg/m³
66Moderate
8:00 PM
💨
PM2.5 21.2 µg/m³
70Moderate
9:00 PM
💨
PM2.5 23.1 µg/m³
74Moderate
10:00 PM
💨
PM2.5 25.4 µg/m³
79Moderate
11:00 PM
💨
PM2.5 27.5 µg/m³
83Moderate
12:00 AM
💨
PM2.5 28.6 µg/m³
86Moderate
1:00 AM
💨
PM2.5 28.2 µg/m³
85Moderate
2:00 AM
💨
PM2.5 26.7 µg/m³
82Moderate
Next few days
daily max · US EPA AQI
Wed
💨
Moderate · UV Very high
83
Thu
💨
Moderate · UV Very high
86
Fri
💨
Moderate · UV Very high
72
Sat
💨
Moderate · UV Very high
85
Sun
💨
Moderate · UV High
67