Today | Weather | Tuesday, July 21, 2026

Weather in Knoxville, Tennessee

05:16 AM
Now
Cloudy Night
73° F
Feels Like 79°
Precipitation 18 %
Wind 6 mph
Humidity 96 %
Today
Cloudy Weather
Day 91°
Night 73°
Precipitation 16 %
Wind 10 mph
UV Index (0 - 11+) 8

Warning: High UV Index Today: 8

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.

Knoxville Weather Forecast Updated

49 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (July 21, 2025)
Stormy Weather

Day

93°

Night

72°

Wind

4 mph

Precipitation

49 %

Air Quality in Knoxville

NOW
26 AQI
Good air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 6.16 µg/m³
PM10 8.95 µg/m³
O3 0.012 ppm
NO2 1.8 ppb
SO2 0.5 ppb
CO 0.10 ppm
NH3 2.51 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)
PM2.56.16 µg/m³
PM108.95 µg/m³
O323.52 µg/m³
NO23.36 µg/m³
SO21.38 µg/m³
CO113.01 µg/m³
NH32.51 µg/m³
NO0 µg/m³