What is the air quality trend in Costa Mesa?

Over the past 8 days, Costa Mesa had an average AQI of 27 based on station measurements. The worst day was 2026-10-20 with AQI 34.

How is Costa Mesa air quality measured?

Air quality in Costa Mesa is measured by ground-level monitoring stations that report PM2.5 and PM10 concentrations hourly. CERNS.IO aggregates readings from nearby stations and converts PM2.5 to the US EPA Air Quality Index (AQI) scale.

Air Quality History for Costa Mesa, United States

Name: Costa Mesa Air Quality History
Creator: CERNS.IO
License: https://creativecommons.org/licenses/by/4.0/

Historical PM2.5 and AQI trend from monitoring stations near Costa Mesa, United States.

Current AQI
Good CAMS model

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

166h

PM2.5 Station

166h · 104 stations

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	PM10 avg	Hours	Stations
2026-10-20	34	23–44	8.2 µg/m³	11.0	21h	92
2026-10-19	29	22–38	7.0 µg/m³	11.0	24h	107
2026-10-18	26	18–35	6.2 µg/m³	11.0	24h	100
2026-10-17	26	16–35	6.2 µg/m³	11.0	24h	107
2026-10-16	29	15–76	7.2 µg/m³	11.0	24h	102
2026-10-15	27	17–40	6.6 µg/m³	11.0	24h	106
2026-10-14	26	18–29	6.1 µg/m³	11.0	24h	105
2026-10-13	23	23–23	5.6 µg/m³	11.0	1h	108

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