Today | Weather | Monday, August 18, 2025

Weather in Fullerton, California

12:08 PM
Now
Sunny WeatherSunny weather, clear skies and sunny weather.
81° F
Feels Like 90°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 11
Humidity 54 %
Today
Sunny WeatherSunny weather, clear skies and sunny weather.
Day 84°
Night 63°
Precipitation 0 %
Wind 6 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.

Fullerton Weather Forecast Updated

28 minutes ago
Last updated on

Weather Forecast History

Last Year's Weather on This Day (August 18, 2024)

Cloudy WeatherCloudy weather, overcast skies with clouds.

Day

84°

Night

70°

Wind

7 mph

UV Index

9

Precipitation

0

Air quality in Fullerton

NOW
58 AQI
Moderate air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 16.45 µg/m³
PM10 19.36 µg/m³
O₃ 44.40 ppb
NO₂ 10.67 ppb
SO₂ 3.07 ppb
CO 142.22 ppb
PM2.5 – 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.