Today | Weather | Tuesday, January 13, 2026

Weather in Costa Mesa, California

12:28 PM
Now
Sunny Weather
70° F
Feels Like 68°
Precipitation 0 %
Wind 17 mph
UV Index (0 - 11+) 3
Humidity 35 %
Today
Sunny Weather
Day 73°
Night 43°
Precipitation 0 %
Wind 14 mph
UV Index (0 - 11+) 3

Costa Mesa Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (January 13, 2025)
Cloudy Weather

Day

68°

Night

45°

Wind

12 mph

UV Index

3

Precipitation

1 %

Air Quality in Costa Mesa

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

Pollutant Concentrations:

PM2.5 34.71 µg/m³
PM10 47.95 µg/m³
O3 0.047 ppm
NO2 10.8 ppb
SO2 1 ppb
CO 0.39 ppm
NH3 0.55 µg/m³
NO 4.93 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 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)
PM2.534.71 µg/m³
PM1047.95 µg/m³
O393.22 µg/m³
NO220.33 µg/m³
SO22.65 µg/m³
CO449.23 µg/m³
NH30.55 µg/m³
NO4.93 µg/m³