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
6.5 µg/m³
WHO guideline 15
PM10
8.9 µg/m³
WHO guideline 45
Hour by hour (12h)
US EPA AQI
4:00 AM
💨
PM2.5 6.5 µg/m³
27Good
5:00 AM
💨
PM2.5 6.8 µg/m³
28Good
6:00 AM
💨
PM2.5 7.5 µg/m³
31Good
7:00 AM
💨
PM2.5 8.3 µg/m³
35Good
8:00 AM
💨
PM2.5 9.6 µg/m³
40Good
9:00 AM
💨
PM2.5 9.8 µg/m³
41Good
10:00 AM
💨
PM2.5 10.6 µg/m³
44Good
11:00 AM
💨
PM2.5 9.9 µg/m³
42Good
12:00 PM
💨
PM2.5 8.5 µg/m³
45Good
1:00 PM
💨
PM2.5 7.8 µg/m³
48Good
2:00 PM
💨
PM2.5 7.3 µg/m³
49Good
3:00 PM
💨
PM2.5 7 µg/m³
50Good
Next few days
daily max · US EPA AQI
Tue
💨
Good · UV Very high
50
Wed
💨
Good · UV Very high
50
Thu
💨
Good · UV Very high
41
Fri
💨
Good · UV Very high
38
Sat
💨
Good · UV Very high
20