Today | Weather | Wednesday, March 18, 2026

Weather in Boston, Massachusetts

12:20 PM
Now
Cloudy Weather
30° F
Feels Like 30°
Precipitation 0 %
Wind 9 mph
UV Index (0 - 11+) 4
Humidity 35 %
Today
Cloudy Weather
Day 36°
Night 27°
Precipitation 0 %
Wind 8 mph
UV Index (0 - 11+) 5
Tomorrow Morning Frost 5 AM – 6 AM

Boston Weather Forecast Updated

56 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (March 18, 2025)
Cloudy Weather

Day

50°

Night

34°

Wind

12 mph

UV Index

5

Precipitation

0 %

Air Quality in Boston

NOW
46 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 0.61 µg/m³
PM10 0.97 µg/m³
O3 0.050 ppm
NO2 1.5 ppb
SO2 0.3 ppb
CO 0.15 ppm
NH3 0.2 µg/m³
NO 0.76 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 considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.50.61 µg/m³
PM100.97 µg/m³
O398.44 µg/m³
NO22.85 µg/m³
SO20.68 µg/m³
CO167.92 µg/m³
NH30.2 µg/m³
NO0.76 µg/m³