Today | Weather | Tuesday, August 18, 2026

Weather in Worcester, Massachusetts

10:38 PM
Now
Cloudy Night
66° F
Feels Like 66°
Precipitation 47 %
Wind 5 mph
Humidity 96 %
Today
Sunny with a Chance of Thunderstorms
Day 81°
Night 61°
Precipitation 55 %
Wind 6 mph
UV Index (0 - 11+) 8

Warning: High UV Index Today: 8

High risk of harm from unprotected sun exposure. Take precautions: wear a hat, sunglasses, and apply sunscreen regularly if you’ll be outdoors for extended periods.

Worcester Weather Forecast Updated

Weather Forecast History
Last Year's Weather on This Day (August 18, 2025)
Cloudy Night

Day

75°

Night

54°

Wind

5 mph

Precipitation

0 %

Air Quality in Worcester

NOW
31 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 4.45 µg/m³
PM10 5.34 µg/m³
O3 0.033 ppm
NO2 3.8 ppb
SO2 0.3 ppb
CO 0.14 ppm
NH3 0.26 µg/m³
NO 0 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)
PM2.54.45 µg/m³
PM105.34 µg/m³
O364.98 µg/m³
NO27.21 µg/m³
SO20.74 µg/m³
CO161.02 µg/m³
NH30.26 µg/m³
NO0 µg/m³