Today | Weather | Wednesday, April 15, 2026

Weather in Thornton, Colorado

04:54 AM
Now
Cloudy Weather
41° F
Feels Like 37°
Precipitation 22 %
Wind 6 mph
Humidity 61 %
Today
Cloudy Weather
Day 68°
Night 43°
Precipitation 3 %
Wind 12 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.

Thornton Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (April 15, 2025)
Cloudy Weather

Day

72°

Night

48°

Wind

6 mph

UV Index

8

Precipitation

2 %

Air Quality in Thornton

NOW
40 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 0.56 µg/m³
PM10 0.61 µg/m³
O3 0.043 ppm
NO2 0.4 ppb
SO2 0 ppb
CO 0.09 ppm
NH3 3.57 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)
PM2.50.56 µg/m³
PM100.61 µg/m³
O384.62 µg/m³
NO20.78 µg/m³
SO20.03 µg/m³
CO107.37 µg/m³
NH33.57 µg/m³
NO0 µg/m³