Bad Air Days in Leavenworth County, Kansas: 1 a Year

1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 637 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (0% particle days).

When the bad days come in Leavenworth

Most bad days here fall in June and May. Averaged over 2016 to 2025.

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 record for Leavenworth

In 2000 to 2009 this county averaged 11 bad days a year; in 2016 to 2025, 1. The air has improved. The worst recent year was 2023, with 10 bad days on 364 monitored days.

Date	AQI	Main pollutant
2023-05-25	129	Ozone
2023-06-09	129	Ozone
2021-06-15	126	Ozone
2023-05-24	112	Ozone
2023-05-27	112	Ozone

The air on a normal day

Across 3,602 monitored days from 2016 to 2025, the air in Leavenworth County rated Good on 93% of them, more often than the 72% typical of monitored counties, and Moderate on 7%. The median day sat at AQI 34; one day in ten went above 49.

The pollutant setting the AQI on an ordinary day here:

ozone100%3,602 days

Leavenworth County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	364	342	22	0	0	34	97
2024	348	327	21	0	0	36	97
2023	364	303	51	10	0	37	129
2022	365	341	24	0	0	37	80
2021	348	330	16	2	0	34	126
2020	366	356	10	0	0	32	77
2019	362	347	15	0	0	33	97
2018	362	325	37	0	0	33	100
2017	361	340	21	0	0	34	74
2016	362	333	29	0	0	35	97
2015	365	347	18	0	0	34	71
2014	363	331	29	3	0	35	105
2013	361	325	35	1	0	36	112
2012	363	270	66	27	2	38	174
2011	360	294	58	8	0	36	147
2010	364	316	45	3	0	36	143

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

Kansas compared

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, and on why a purifier does not touch ozone in smoke vs ozone.