Today | Weather | Thursday, May 21, 2026

Weather in Pittsburgh, Pennsylvania

11:20 AM
Now
Cloudy Weather
59° F
Feels Like 61°
Precipitation 40 %
Wind 8 mph
UV Index (0 - 11+) 3
Humidity 66 %
Today
Cloudy Weather
Day 64°
Night 54°
Precipitation 55 %
Wind 7 mph
UV Index (0 - 11+) 10

Warning: High UV Index Today: 10

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.

Pittsburgh Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (May 21, 2025)
Stormy Weather

Day

73°

Night

54°

Wind

8 mph

UV Index

10

Precipitation

99 %

Air Quality in Pittsburgh

NOW
14 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.9 µg/m³
PM10 2.04 µg/m³
O3 0.015 ppm
NO2 3.5 ppb
SO2 0.7 ppb
CO 0.13 ppm
NH3 0.19 µg/m³
NO 1.21 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)
PM2.51.9 µg/m³
PM102.04 µg/m³
O330.39 µg/m³
NO26.54 µg/m³
SO21.83 µg/m³
CO144.56 µg/m³
NH30.19 µg/m³
NO1.21 µg/m³