Today | Weather | Friday, October 30, 2026

Weather in Costa Mesa, California

07:52 PM
Now
Cloudy Night
66° F
Feels Like 64°
Precipitation 17 %
Wind 6 mph
Humidity 72 %
Today
Rainy Weather
Day 72°
Night 61°
Precipitation 55 %
Wind 5 mph

Costa Mesa Weather Forecast Updated

28 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (October 30, 2025)
Foggy Weather

Day

79°

Night

55°

Wind

5 mph

Precipitation

0 %

Air Quality in Costa Mesa

NOW
47 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.47 µg/m³
PM10 5.63 µg/m³
O3 0.051 ppm
NO2 0.2 ppb
SO2 0.1 ppb
CO 0.11 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)
PM2.5 – 2.47 µg/m³
PM10 – 5.63 µg/m³
O3 – 99.75 µg/m³
NO2 – 0.3 µg/m³
SO2 – 0.23 µg/m³
CO – 120.75 µg/m³
NH3 – 0 µg/m³
NO – 0 µg/m³