Today | Weather | Sunday, April 26, 2026

Weather in Ontario, California

09:57 AM
Now
Partly Sunny with Showers
55° F
Feels Like 52°
Precipitation 42 %
Wind 8 mph
UV Index (0 - 11+) 2
Humidity 74 %
Today
Cloudy Weather
Day 64°
Night 48°
Precipitation 49 %
Wind 12 mph
UV Index (0 - 11+) 5

Ontario Weather Forecast Updated

47 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (April 26, 2025)
Stormy Weather

Day

57°

Night

46°

Wind

12 mph

UV Index

3

Precipitation

97 %

Air Quality in Ontario

NOW
57 AQI
Moderate air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 0.51 µg/m³
PM10 1.16 µg/m³
O3 0.056 ppm
NO2 0.2 ppb
SO2 0.1 ppb
CO 0.11 ppm
NH3 0.01 µg/m³
NO 0.04 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)
PM2.50.51 µg/m³
PM101.16 µg/m³
O3110.69 µg/m³
NO20.3 µg/m³
SO20.34 µg/m³
CO126.1 µg/m³
NH30.01 µg/m³
NO0.04 µg/m³