What is the air quality trend in Walnut Creek?

Over the past 15 days, Walnut Creek had an average AQI of 28 based on station measurements. The worst day was 2026-07-16 with AQI 42.

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

335h

PM2.5 Station

335h · 1 station

Temperature GFS model

56pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	PM10 avg	Hours	Stations
2026-07-22	5	5–5	1.1 µg/m³	1.1	1h	1
2026-07-21	30	23–60	7.2 µg/m³	4.9	24h	97
2026-07-20	22	16–76	5.6 µg/m³	2.8	24h	91
2026-07-19	26	20–41	6.2 µg/m³	4.3	24h	95
2026-07-18	27	20–38	6.5 µg/m³	3.4	24h	97
2026-07-17	36	33–42	8.7 µg/m³	8.7	24h	98
2026-07-16	42	31–200	14.4 µg/m³	6.8	24h	91
2026-07-15	35	30–56	8.5 µg/m³	5.9	24h	94
2026-07-14	33	30–43	7.9 µg/m³	9.1	24h	93
2026-07-13	29	25–39	7.0 µg/m³	5.4	24h	95
2026-07-12	24	21–30	5.8 µg/m³	2.7	24h	90
2026-07-11	25	16–53	6.0 µg/m³	1.8	24h	74
2026-07-10	37	27–58	8.9 µg/m³	7.0	24h	90
2026-07-09	24	17–33	5.7 µg/m³	3.0	23h	97
2026-07-08	27	24–30	6.4 µg/m³	3.3	23h	98

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