What is the air quality in Waltham today?

The current Air Quality Index (AQI) in Waltham is 13 (Good). PM2.5 concentration is 3.12 µg/m³.

What is the temperature in Waltham right now?

The current temperature in Waltham is 6.6°C (feels like 3.3°C). Humidity is 59.8% and wind speed is 18.1 km/h.

Is it safe to go outside in Waltham?

Air quality is satisfactory. Enjoy outdoor activities. The UV Index is 0.0 (Low).

Air Quality in Waltham, United States

Partly Cloudy

6.6°C · 59.8% humidity

6.6°

Feels 3.3°

Good

Air quality is satisfactory. Enjoy outdoor activities.

3 stations

Nearby Monitoring Stations

AQI Forecast

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Station readings

Air Quality Index Trend

47h · 1 stn

View full history →

Waltham's air quality is primarily affected by vehicle emissions and industrial activity. Seasonal wildfire smoke and weather patterns can cause periodic air quality deterioration.

59.8%

Humidity

18.1 km/h

Wind SSE

1029.6 hPa

Pressure

0.0

UV Low

GoodModerateUSGUnhealthyVery UnhealthyHazardous

Which pollutant is driving the AQI?

PM2.5▲

3.12 µg/m³

PM10

13.7 µg/m³

050100150200300500

What is the weather forecast for Waltham?

Temperature & Precipitation

PM2.5 Trend

47h · 1 station

PM2.53.12 µg/m³ ✓ WHO

Good

PM1013.7 µg/m³

Good

UV INDEX0.0

Low

Station readings (3 stations within 25 km)

3.12

Median

2.88

Average

0.75

Low

5.0

High

PM2.5 µg/m³ · Model: 5.8 · Bias: +2.7

Both models agree Avg diff: 4.5°C

Where are air quality stations near Waltham?

Boston Roxbury

13.6 km PM2.5: 5.3 µg/m³

Boston Roxbury

13.6 km PM2.5: 5.0 µg/m³

Boston Roxbury

13.6 km PM2.5: 4.3 µg/m³

East Dedham

15.6 km 15.8°C 50.0% RH PM2.5: 0.8 µg/m³ PM10: 1.3 µg/m³

Lynn Water Treatment Plant

24.3 km PM2.5: 4.3 µg/m³

Lynn Water Treatment Plant

24.3 km PM2.5: 2.9 µg/m³

What cities are near Waltham?

15 Watertown 15 Belmont 16 Brighton 14 Chestnut Hill 18 Allston 9 Wellesley 7 Needham 19 Brookline 18 Cambridge 18 Somerville

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Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-10-20T21:44 UTC.