Today | Weather | Tuesday, December 30, 2025

Weather in Ontario, California

03:24 PM
Now
Cloudy Weather
66° F
Feels Like 63°
Precipitation 47 %
Wind 16 mph
UV Index (0 - 11+) 1
Humidity 33 %
Today
Partly Sunny with Showers
Day 66°
Night 57°
Precipitation 87 %
Wind 9 mph
UV Index (0 - 11+) 1

Ontario Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (December 30, 2024)
Cloudy Weather

Day

64°

Night

41°

Wind

4 mph

UV Index

3

Precipitation

40 %

Air Quality in Ontario

NOW
56 AQI
Moderate air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 15.02 µg/m³
PM10 25.13 µg/m³
O3 0.019 ppm
NO2 32.1 ppb
SO2 2 ppb
CO 0.33 ppm
NH3 1.18 µg/m³
NO 5.1 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 acceptable; however, for some pollutants, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

Show raw pollutant concentrations (µg/m³)
PM2.515.02 µg/m³
PM1025.13 µg/m³
O336.76 µg/m³
NO260.36 µg/m³
SO25.29 µg/m³
CO383.61 µg/m³
NH31.18 µg/m³
NO5.1 µg/m³