Today | Weather | Wednesday, May 20, 2026

Active Weather Warnings

Severe Thunderstorm Watch

Weather in Danbury, Connecticut

05:51 PM

Now

79° F

Feels Like 81°

Precipitation 47 %

Wind 9 mph

UV Index (0 - 11+) 1

Humidity 62 %

Today

Day 86°

Night 57°

Precipitation 55 %

Wind 9 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.

Danbury Weather Forecast Updated

Last updated on May 20, 2026 at 4:44 PM

Air Quality in Danbury

NOW

37 AQI

Good air quality Dominant pollutant: O₃

Pollutant Concentrations:

PM_2.5 4.41 µg/m³

PM₁₀ 5.38 µg/m³

O₃ 0.040 ppm

NO₂ 4.5 ppb

SO₂ 0.7 ppb

CO 0.13 ppm

NH₃ 0.36 µg/m³

NO 0.09 µg/m³

PM_2.5 – 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)

PM_2.5 – 4.41 µg/m³

PM₁₀ – 5.38 µg/m³

O₃ – 78.96 µg/m³

NO₂ – 8.41 µg/m³

SO₂ – 1.96 µg/m³

CO – 152.82 µg/m³

NH₃ – 0.36 µg/m³

NO – 0.09 µg/m³

View Hourly Air Quality Forecast

Weather Alerts and Warnings for Danbury

Severe Future Possible

Severe Thunderstorm Watch

Severe Thunderstorm Watch issued May 20 at 2:11PM EDT until May 20 at 9:00PM EDT by NWS Upton NY

May 20, 2:11 PM → May 20, 9:00 PM

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH
235 IN EFFECT UNTIL 9 PM EDT THIS EVENING FOR THE FOLLOWING AREAS

IN CONNECTICUT THIS WATCH INCLUDES 4 COUNTIES

IN SOUTHERN CONNECTICUT

FAIRFIELD MIDDLESEX NEW HAVEN
NEW LONDON

IN NEW JERSEY THIS WATCH INCLUDES 5 COUNTIES

IN NORTHEAST NEW JERSEY

BERGEN ESSEX HUDSON
PASSAIC UNION

IN NEW YORK THIS WATCH INCLUDES 11 COUNTIES

IN SOUTHEAST NEW YORK

BRONX KINGS (BROOKLYN) NASSAU
NEW YORK (MANHATTAN) ORANGE PUTNAM
QUEENS RICHMOND (STATEN ISLAND)
ROCKLAND SUFFOLK WESTCHESTER

Updated: May 20, 4:44 PM Source: NWS Alert