Air quality in Waltham
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
13 µg/m³
WHO guideline 15
PM10
13.5 µg/m³
WHO guideline 45
Hour by hour (12h)
US EPA AQI
12:00 AM
💨
PM2.5 13 µg/m³
53Moderate
1:00 AM
💨
PM2.5 12.7 µg/m³
52Moderate
2:00 AM
💨
PM2.5 12.4 µg/m³
52Moderate
3:00 AM
💨
PM2.5 12.2 µg/m³
51Moderate
4:00 AM
💨
PM2.5 12.1 µg/m³
51Moderate
5:00 AM
💨
PM2.5 12.3 µg/m³
51Moderate
6:00 AM
💨
PM2.5 12.5 µg/m³
52Moderate
7:00 AM
💨
PM2.5 13.4 µg/m³
54Moderate
8:00 AM
💨
PM2.5 13.8 µg/m³
55Moderate
9:00 AM
💨
PM2.5 11.3 µg/m³
47Good
10:00 AM
💨
PM2.5 10.8 µg/m³
60Moderate
11:00 AM
💨
PM2.5 10.9 µg/m³
95Moderate
Next few days
daily max · US EPA AQI
Thu
💨
Unhealthy for Sensitive Groups · UV High
115
Fri
💨
Unhealthy for Sensitive Groups · UV High
111
Sat
💨
Moderate · UV Low
68
Sun
💨
Moderate · UV High
96
Mon
💨
Moderate · UV High
56