What is the air quality trend in Walnut Creek?

Over the past 8 days, Walnut Creek had an average AQI of 28 based on station measurements. The worst day was 2026-10-18 with AQI 35.

How is Walnut Creek air quality measured?

Air quality in Walnut Creek 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 Walnut Creek, United States

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

Historical PM2.5 and AQI trend from monitoring stations near Walnut Creek, United States.

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

165h

PM2.5 Station

165h · 96 stations

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	PM10 avg	Hours	Stations
2026-10-21	30	26–38	7.1 µg/m³	2.9	10h	100
2026-10-20	22	17–50	5.2 µg/m³	5.4	24h	89
2026-10-19	23	20–28	5.6 µg/m³	11.7	24h	99
2026-10-18	35	20–43	8.3 µg/m³	20.3	24h	91
2026-10-17	30	25–37	7.3 µg/m³	12.8	24h	101
2026-10-16	32	24–43	7.7 µg/m³	12.3	24h	97
2026-10-15	28	24–37	6.8 µg/m³	12.3	24h	104
2026-10-14	26	22–29	6.4 µg/m³	14.2	11h	105

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