What is the air quality trend in Watertown?

Over the past 7 days, Watertown had an average AQI of 42 based on station measurements. The worst day was 2026-08-07 with AQI 55.

How is Watertown air quality measured?

Air quality in Watertown 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 Watertown, United States

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

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

Current AQI
Good CAMS model

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

119h

PM2.5 Station

119h · 1 station

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-08-07	55	21–109	15.5 µg/m³	14h	2
2026-08-06	39	1–71	9.8 µg/m³	20h	2
2026-08-05	36	13–76	9.2 µg/m³	19h	2
2026-08-04	48	4–192	16.1 µg/m³	22h	2
2026-08-03	47	6–161	14.0 µg/m³	19h	2
2026-08-02	36	10–74	9.1 µg/m³	15h	2
2026-08-01	34	8–61	8.5 µg/m³	10h	2

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