Bad Air Days in Delaware County, Iowa

Not enough data

EPA monitors in Delaware County ran on too few days between 2016 and 2025 to give a fair yearly count (about 25% of days covered). Neighbouring counties below are a better guide.

What to buy, and what not to

EPA monitors here ran too few days to give a fair yearly count. Use AirNow for today's air.

The record for Delaware

Date	AQI	Main pollutant
2016-01-25	81	PM2.5
2016-02-15	78	PM2.5
2017-02-06	70	PM2.5
2016-03-04	66	PM2.5
2016-02-18	65	PM2.5

Most days, not the worst ones

Across 182 monitored days from 2016 to 2017, the air in Delaware County rated Good on 78% of them, more often than the 72% typical of monitored counties, and Moderate on 22%. The median day sat at AQI 30; one day in ten went above 57.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)87%159 days
coarse dust (PM10)13%23 days

Delaware County by year

Year	Days monitored	Good	Moderate	Median AQI	Highest AQI
2017	54	43	11	29	70
2016	128	99	29	31	81
2015	118	80	38	38	76
2014	126	76	50	43	80
2013	119	70	49	46	90
2012	124	75	49	42	79
2011	120	62	58	48	86
2010	114	113	1	15	53

Iowa 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.