What is the air quality trend in Crystal Lake?

Over the past 8 days, Crystal Lake had an average AQI of 31 based on station measurements. The worst day was 2026-10-21 with AQI 53.

How is Crystal Lake air quality measured?

Air quality in Crystal Lake 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 Crystal Lake, United States

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

Historical PM2.5 and AQI trend from monitoring stations near Crystal Lake, 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 · 83 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	53	53–53	12.9 µg/m³	1.0	1h	83
2026-10-20	51	18–73	13.5 µg/m³	—	24h	74
2026-10-19	29	22–45	6.8 µg/m³	—	24h	84
2026-10-18	24	18–38	5.7 µg/m³	—	24h	78
2026-10-17	16	13–25	3.9 µg/m³	—	24h	84
2026-10-16	19	11–38	4.5 µg/m³	—	24h	80
2026-10-15	24	14–40	5.9 µg/m³	—	24h	84
2026-10-14	35	18–52	8.5 µg/m³	1.3	20h	85

Back to Crystal Lake Air Quality