Today | Weather | Thursday, October 30, 2025

Weather in Ontario, California

11:31 AM

Now

82° F

Feels Like 88°

Precipitation 0 %

Wind 5 mph

UV Index (0 - 11+) 4

Humidity 16 %

Today

Day 90°

Night 57°

Precipitation 0 %

Wind 6 mph

UV Index (0 - 11+) 4

Ontario Weather Forecast Updated

30 minutes ago

Last updated on October 30, 2025 11:01 AM

Weather Forecast History

Last Year's Weather on This Day (October 30, 2024)

Day

72°

Night

48°

Wind

4 mph

Precipitation

Air Quality in Ontario

NOW

74 AQI

Moderate air quality Dominant pollutant: PM_2.5

Pollutant Concentrations:

PM_2.5 23.03 µg/m³

PM₁₀ 34.55 µg/m³

O₃ 0.044 ppm

NO₂ 0.5 ppb

SO₂ 0.2 ppb

CO 0.18 ppm

NH₃ 0.03 µg/m³

NO 0.17 µg/m³

PM_2.5 – 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)

PM_2.5 – 23.03 µg/m³

PM₁₀ – 34.55 µg/m³

O₃ – 85.73 µg/m³

NO₂ – 0.94 µg/m³

SO₂ – 0.41 µg/m³

CO – 202.75 µg/m³

NH₃ – 0.03 µg/m³

NO – 0.17 µg/m³

View Hourly Air Quality Forecast