Today | Weather | Friday, June 5, 2026

Weather in Ontario, California

06:08 PM
Now
Sunny Weather
79° F
Feels Like 79°
Precipitation 0 %
Wind 10 mph
UV Index (0 - 11+) 2
Humidity 47 %
Today
Sunny Weather
Day 82°
Night 57°
Precipitation 1 %
Wind 8 mph
UV Index (0 - 11+) 11

Warning: Extreme UV Index Today: 11+

Overexposure to the sun's harmful UV rays can cause sunburn and increase the risk of developing skin cancer, including melanoma. Protect yourself by wearing clothing that covers your skin, sunglasses, and a hat. Apply a broad-spectrum sunscreen with an SPF of 30 or higher every two hours, even on cloudy days. Minimize direct sun exposure during peak hours (10 AM to 4 PM) to reduce the risk.

Ontario Weather Forecast Updated

47 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (June 5, 2025)
Cloudy Weather

Day

77°

Night

57°

Wind

7 mph

UV Index

12

Precipitation

40 %

Air Quality in Ontario

NOW
41 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 5.91 µg/m³
PM10 17.35 µg/m³
O3 0.045 ppm
NO2 0.1 ppb
SO2 0.2 ppb
CO 0.09 ppm
NH3 0 µg/m³
NO 0.02 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)
PM2.55.91 µg/m³
PM1017.35 µg/m³
O387.79 µg/m³
NO20.24 µg/m³
SO20.61 µg/m³
CO102.79 µg/m³
NH30 µg/m³
NO0.02 µg/m³