Today | Weather | Monday, September 21, 2026

Weather in Danbury, Connecticut

01:54 PM
Now
Cloudy Weather
68° F
Feels Like 70°
Precipitation 0 %
Wind 12 mph
UV Index (0 - 11+) 5
Humidity 47 %
Today
Cloudy Weather
Day 70°
Night 54°
Precipitation 2 %
Wind 9 mph
UV Index (0 - 11+) 5

Danbury Weather Forecast Updated

10 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (September 21, 2025)
Cloudy Night

Day

70°

Night

45°

Wind

2 mph

Precipitation

0 %

Air Quality in Danbury

NOW
35 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 4.69 µg/m³
PM10 6.74 µg/m³
O3 0.037 ppm
NO2 5.1 ppb
SO2 1.3 ppb
CO 0.20 ppm
NH3 0.4 µg/m³
NO 1.2 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)
PM2.54.69 µg/m³
PM106.74 µg/m³
O373.56 µg/m³
NO29.69 µg/m³
SO23.43 µg/m³
CO227.51 µg/m³
NH30.4 µg/m³
NO1.2 µg/m³