Bad Air Days in Cass County, Nebraska: 0 a Year

0 bad air days a year

Rare: among the cleanest-air counties EPA monitors. Ranked 967 of 996 monitored counties, where 1 is worst.

Is a purifier worth it here?

Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
On the odd bad day, check AirNow and keep windows shut.

The worst days on file

In 2000 to 2009 this county averaged under 1 bad days a year; in 2016 to 2025, 0. Not much has changed.

Date	AQI	Main pollutant
2016-02-19	99	PM10
2016-12-29	90	PM10
2022-11-22	87	PM10
2017-11-30	83	PM10
2017-12-04	80	PM10

Most days, not the worst ones

Across 3,434 monitored days from 2016 to 2025, the air in Cass County rated Good on 96% of them, more often than the 72% typical of monitored counties, and Moderate on 4%. The median day sat at AQI 18; one day in ten went above 37.

The pollutant setting the AQI on an ordinary day here:

coarse dust (PM10)100%3,434 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	339	325	14	0	0	19	64
2024	274	259	15	0	0	17	68
2023	354	344	10	0	0	17	66
2022	356	337	19	0	0	19	87
2021	351	345	6	0	0	19	64
2020	358	346	12	0	0	14	71
2019	348	348	0	0	0	13	46
2018	337	332	5	0	0	15	57
2017	365	335	30	0	0	22	83
2016	352	322	30	0	0	22	99
2015	353	309	43	1	0	24	106
2014	357	316	41	0	0	22	96
2013	355	334	21	0	0	22	77
2012	346	293	52	1	0	27	113
2011	285	257	28	0	0	22	77
2010	308	285	19	4	1	21	176

*2025 may be a partial year in EPA's file.

Nearby counties on file

How this is counted

A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day.