Today | Weather | Thursday, November 20, 2025

Weather in Ontario, California

10:59 AM
Now
Cloudy Weather
55° F
Feels Like 57°
Precipitation 47 %
Wind 5 mph
UV Index (0 - 11+) 1
Humidity 79 %
Today
Rainy Weather
Day 55°
Night 52°
Precipitation 96 %
Wind 5 mph
UV Index (0 - 11+) 1

Ontario Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (November 20, 2024)
Cloudy Night

Day

72°

Night

48°

Wind

4 mph

Precipitation

0 %

Air Quality in Ontario

NOW
45 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.15 µg/m³
PM10 3.88 µg/m³
O3 0.049 ppm
NO2 0.1 ppb
SO2 0.1 ppb
CO 0.09 ppm
NH3 0 µg/m³
NO 0.01 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)
PM2.51.15 µg/m³
PM103.88 µg/m³
O395.54 µg/m³
NO20.25 µg/m³
SO20.24 µg/m³
CO104.93 µg/m³
NH30 µg/m³
NO0.01 µg/m³