Today | Weather | Tuesday, October 14, 2025

Weather in Costa Mesa, California

06:46 PM
Now
Cloudy Night
63° F
Feels Like 63°
Precipitation 47 %
Wind 5 mph
Humidity 73 %
Today
Stormy Weather
Day 64°
Night 55°
Precipitation 100 %
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.

Costa Mesa Weather Forecast Updated

45 minutes ago
Last updated on

Air Quality in Costa Mesa

NOW
40 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.76 µg/m³
PM10 5.18 µg/m³
O3 0.043 ppm
NO2 0.1 ppb
SO2 0.1 ppb
CO 0.09 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 considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.51.76 µg/m³
PM105.18 µg/m³
O384.6 µg/m³
NO20.24 µg/m³
SO20.17 µg/m³
CO100.22 µg/m³
NH30 µg/m³
NO0 µg/m³