Today | Weather | Thursday, May 21, 2026

Weather in Hartford, Connecticut

05:08 AM
Now
Cloudy Weather
61° F
Feels Like 59°
Precipitation 40 %
Wind 7 mph
Humidity 53 %
Today
Rainy Weather
Day 64°
Night 48°
Precipitation 60 %
Wind 6 mph
UV Index (0 - 11+) 3

Hartford Weather Forecast Updated

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

Day

54°

Night

46°

Wind

8 mph

UV Index

2

Precipitation

55 %

Air Quality in Hartford

NOW
31 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.93 µg/m³
PM10 3.11 µg/m³
O3 0.034 ppm
NO2 3.5 ppb
SO2 0.9 ppb
CO 0.12 ppm
NH3 1 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)
PM2.51.93 µg/m³
PM103.11 µg/m³
O366.43 µg/m³
NO26.62 µg/m³
SO22.27 µg/m³
CO135.47 µg/m³
NH31 µg/m³
NO0 µg/m³