Today | Weather | Friday, December 12, 2025

Weather in Rancho Cucamonga, California

11:18 AM
Now
Sunny Weather
72° F
Feels Like 73°
Precipitation 0 %
Wind 5 mph
UV Index (0 - 11+) 3
Humidity 25 %
Today
Sunny Weather
Day 81°
Night 52°
Precipitation 0 %
Wind 4 mph
UV Index (0 - 11+) 3

Rancho Cucamonga Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (December 12, 2024)
Cloudy Night

Day

59°

Night

43°

Wind

6 mph

Precipitation

25 %

Air Quality in Rancho Cucamonga

NOW
169 AQI
Unhealthy air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 91.21 µg/m³
PM10 101.27 µg/m³
O3 0.051 ppm
NO2 2.5 ppb
SO2 1 ppb
CO 0.47 ppm
NH3 0.2 µg/m³
NO 0.5 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:

Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.

Show raw pollutant concentrations (µg/m³)
PM2.591.21 µg/m³
PM10101.27 µg/m³
O399.96 µg/m³
NO24.64 µg/m³
SO22.75 µg/m³
CO538.91 µg/m³
NH30.2 µg/m³
NO0.5 µg/m³