Bad Air Days in Andrew County, Missouri: 1 a Year

1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 612 of 996 monitored counties, where 1 is worst.

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

Which months to watch

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

What actually helps 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 Andrew

In 2000 to 2009 this county averaged 0 bad days a year; in 2016 to 2025, 1. Not much has changed. The worst recent year was 2023, with 6 bad days on 244 monitored days.

Date	AQI	Main pollutant
2023-06-03	122	Ozone
2023-06-06	119	Ozone
2018-06-01	112	Ozone
2023-06-04	112	Ozone
2023-06-20	108	Ozone

Most days, not the worst ones

Across 2,435 monitored days from 2016 to 2025, the air in Andrew County rated Good on 86% of them, more often than the 72% typical of monitored counties, and Moderate on 14%. The median day sat at AQI 41; one day in ten went above 58.

The pollutant setting the AQI on an ordinary day here:

ozone100%2,435 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	245	213	32	0	0	40	93
2024	264	227	37	0	0	42	100
2023	244	176	62	6	0	43	122
2022	245	213	31	1	0	43	101
2021	245	225	20	0	0	39	90
2020	245	225	20	0	0	38	77
2019	245	227	18	0	0	40	80
2018	245	186	58	1	0	42	112
2017	243	203	39	1	0	42	101
2016	214	188	26	0	0	40	100
2015	213	184	29	0	0	40	87
2014	212	182	30	0	0	39	100
2013	214	176	35	3	0	42	115
2012	214	135	62	17	1	46	151
2011	239	186	45	8	0	42	147
2010	210	166	38	6	0	41	136

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

Missouri 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.