Today | Weather | Wednesday, March 18, 2026

Weather in Somerville, Massachusetts

06:10 PM
Now
Cloudy Weather
36° F
Feels Like 30°
Precipitation 0 %
Wind 8 mph
UV Index (0 - 11+) 1
Humidity 32 %
Today
Cloudy Weather
Day 37°
Night 25°
Precipitation 0 %
Wind 9 mph
UV Index (0 - 11+) 4
Tomorrow Morning Frost 5 AM – 7 AM

Somerville Weather Forecast Updated

Last updated on

Air Quality in Somerville

NOW
52 AQI
Moderate air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.87 µg/m³
PM10 2.24 µg/m³
O3 0.055 ppm
NO2 1.3 ppb
SO2 0.3 ppb
CO 0.15 ppm
NH3 0.11 µg/m³
NO 0.23 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is acceptable; however, for some pollutants, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

Show raw pollutant concentrations (µg/m³)
PM2.51.87 µg/m³
PM102.24 µg/m³
O3107.26 µg/m³
NO22.46 µg/m³
SO20.69 µg/m³
CO167.2 µg/m³
NH30.11 µg/m³
NO0.23 µg/m³