Air Quality in Waltham, United States
Rain
16.9°C · 96.5% humidity
16.9°
Feels 16.9°
55
Moderate
Unusually sensitive people should consider reducing prolonged outdoor exertion.
5 stations
Nearby Monitoring Stations
AQI Forecast
Calibrated
63
3pm
63
63
55
6pm
57
59
60
9pm
54
54
53
12am
53
52
53
3am
53
53
53
6am
53
53
53
9am
53
53
53
12pm
54
54
Station readings
65
71
56
CAMS model
adj +29
34
34
34
34
34
34
34
27
27
25
25
24
24
24
24
24
24
24
24
24
24
24
25
25
Air Quality Index Trend
47h · 1 stnWaltham's air quality is primarily affected by vehicle emissions and industrial activity. Seasonal wildfire smoke and weather patterns can cause periodic air quality deterioration.
96.5%
Humidity
76.4 km/h
Wind NNE
1012.7 hPa
Pressure
2.2
UV Moderate
GoodModerateUSGUnhealthyVery UnhealthyHazardous
Which pollutant is driving the AQI?
PM2.5▲
14.15 µg/m³
PM10
27.45 µg/m³
050100150200300500
What is the weather forecast for Waltham?
Temperature & Precipitation
PM2.5 Trend
47h · 1 stationPM2.514.15 µg/m³
✓ WHO
Moderate
PM1027.45 µg/m³
Good
UV INDEX2.2
Moderate
Station readings (5 stations within 25 km)
14.15
Median
12.75
Average
9.6
Low
18.24
High
PM2.5 µg/m³ · Model: 13.7 · Bias: -0.4
What is the 7-day forecast for Waltham?
07-21
27.2° 18.8°
4.19 mm
07-22
22.7° 14.9°
9.25 mm
07-23
27.7° 16.7°
1.81 mm
07-24
26.5° 14.9°
2.31 mm
07-25
35.5° 20.6°
2.88 mm
07-26
23.5° 17.0°
1.63 mm
07-27
28.8° 14.9°
5.94 mm
Both models agree
Avg diff: 3.4°C
Where are air quality stations near Waltham?
56
Magazine Beach Park
53
Nubian Square - DEP Station
9
Boston Roxbury
52
Boston
42
Boston
32
Milton Blue Hill Observatory
What cities are near Waltham?
Get AQI alerts for Waltham
Notify me when air quality reaches:
Free · No account · Unsubscribe any time
Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-07-21T22:17 UTC.