Today | Weather | Monday, April 6, 2026

Weather in Ontario, California

05:48 AM
Now
Cloudy Night
61° F
Feels Like 59°
Precipitation 0 %
Wind 6 mph
Humidity 56 %
Today
Cloudy Weather
Day 81°
Night 54°
Precipitation 0 %
Wind 9 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.

Ontario Weather Forecast Updated

31 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (April 6, 2025)
Sunny Weather

Day

81°

Night

52°

Wind

7 mph

UV Index

8

Precipitation

1 %

Air Quality in Ontario

NOW
67 AQI
Moderate air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 15.1 µg/m³
PM10 29 µg/m³
O3 0.059 ppm
NO2 0.3 ppb
SO2 0.5 ppb
CO 0.13 ppm
NH3 0 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 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)
PM2.515.1 µg/m³
PM1029 µg/m³
O3116.46 µg/m³
NO20.52 µg/m³
SO21.28 µg/m³
CO145.04 µg/m³
NH30 µg/m³
NO0 µg/m³