Today | Weather | Monday, September 21, 2026

Weather in Portsmouth, Virginia

01:57 PM
Now
Cloudy Weather
82° F
Feels Like 91°
Precipitation 15 %
Wind 10 mph
UV Index (0 - 11+) 5
Humidity 68 %
Today
Sunny with a Chance of Thunderstorms
Day 84°
Night 72°
Precipitation 55 %
Wind 8 mph
UV Index (0 - 11+) 6

Portsmouth Weather Forecast Updated

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

Day

75°

Night

63°

Wind

7 mph

Precipitation

1 %

Air Quality in Portsmouth

NOW
44 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 4.7 µg/m³
PM10 6.69 µg/m³
O3 0.047 ppm
NO2 0.3 ppb
SO2 0.2 ppb
CO 0.13 ppm
NH3 0.58 µg/m³
NO 0.09 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)
PM2.54.7 µg/m³
PM106.69 µg/m³
O393.19 µg/m³
NO20.61 µg/m³
SO20.58 µg/m³
CO154.15 µg/m³
NH30.58 µg/m³
NO0.09 µg/m³