Today | Weather | Saturday, September 13, 2025

Weather in Ontario, California

02:08 AM

Now

63° F

Feels Like 63°

Precipitation 0 %

Wind 5 mph

Humidity 94 %

Today

Day 84°

Night 61°

Precipitation 1 %

Wind 11

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

Last updated on September 13, 2025 1:05 AM

Weather Forecast History

Last Year's Weather on This Day (September 13, 2024)

Day

82°

Night

59°

Wind

7 mph

UV Index

Precipitation

Air quality in Ontario

NOW

54 AQI

Moderate air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 19.63 µg/m³

PM10 21.44 µg/m³

O₃ 18.10 ppb

NO₂ 19.33 ppb

SO₂ 4.14 ppb

CO 208.10 ppb

PM_2.5 – Fine particles <2.5μm

PM₁₀ – Inhalable particles <10μm

O₃ – Ozone

NO₂ – Nitrogen dioxide

SO₂ – Sulfur dioxide

CO – Carbon monoxide

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

View Hourly Air Quality Forecast