Today | Weather | Thursday, May 21, 2026

Weather in Stamford, Connecticut

11:19 AM
Now
Rainy Weather
59° F
Feels Like 55°
Precipitation 81 %
Wind 9 mph
UV Index (0 - 11+) 2
Humidity 77 %
Today
Rainy Weather
Day 63°
Night 54°
Precipitation 97 %
Wind 7 mph
UV Index (0 - 11+) 3

Stamford Weather Forecast Updated

58 seconds ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (May 21, 2025)
Rainy Weather

Day

55°

Night

48°

Wind

12 mph

UV Index

2

Precipitation

97 %

Air Quality in Stamford

NOW
26 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.84 µg/m³
PM10 4.78 µg/m³
O3 0.028 ppm
NO2 10.1 ppb
SO2 1.7 ppb
CO 0.15 ppm
NH3 1.21 µg/m³
NO 2.46 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)
PM2.52.84 µg/m³
PM104.78 µg/m³
O354.36 µg/m³
NO219 µg/m³
SO24.43 µg/m³
CO174.62 µg/m³
NH31.21 µg/m³
NO2.46 µg/m³