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
9.5 µg/m³
WHO guideline 15
PM10
9.7 µg/m³
WHO guideline 45
Hour by hour (12h)
US EPA AQI
9:00 AM
💨
PM2.5 9.5 µg/m³
40Good
10:00 AM
💨
PM2.5 9.1 µg/m³
44Good
11:00 AM
💨
PM2.5 7.6 µg/m³
55Moderate
12:00 PM
💨
PM2.5 6.5 µg/m³
60Moderate
1:00 PM
💨
PM2.5 5.9 µg/m³
53Moderate
2:00 PM
💨
PM2.5 5.5 µg/m³
48Good
3:00 PM
💨
PM2.5 5.6 µg/m³
53Moderate
4:00 PM
💨
PM2.5 6.3 µg/m³
60Moderate
5:00 PM
💨
PM2.5 7.7 µg/m³
65Moderate
6:00 PM
💨
PM2.5 10 µg/m³
65Moderate
7:00 PM
💨
PM2.5 11.9 µg/m³
63Moderate
8:00 PM
💨
PM2.5 13.1 µg/m³
56Moderate
Next few days
daily max · US EPA AQI
Sun
💨
Moderate · UV High
65
Mon
💨
Moderate · UV High
56
Tue
💨
Moderate · UV Low
53
Wed
💨
Good · UV Moderate
50
Thu
💨
Moderate · UV Moderate
51