Bad Air Days in Douglas County, Oregon: 4 a Year

4 bad air days a year

About the middle of monitored US counties. Ranked 273 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (100% particle days).

When the bad days come in Douglas

Most bad days here fall in September and August. Averaged over 2016 to 2025.

Is a purifier worth it here?

Particles (wildfire smoke, dust) cause enough bad days here to matter. A HEPA purifier sized to your bedroom removes them; run it with windows shut on bad days.
Upgrade the furnace or AC filter to MERV 13 so the whole house is filtered, not just one room.

The worst days on file

In 2000 to 2009 this county averaged under 1 bad days a year; in 2016 to 2025, 4. It has got worse. The worst recent year was 2020, with 10 bad days on 366 monitored days.

Date	AQI	Main pollutant
2020-09-13	902	PM2.5
2020-09-12	683	PM2.5
2020-09-14	529	PM2.5
2020-09-10	500	PM2.5
2020-09-09	452	PM2.5

The air on a normal day

Across 2,158 monitored days from 2016 to 2022, the air in Douglas County rated Good on 78% of them, more often than the 72% typical of monitored counties, and Moderate on 21%. The median day sat at AQI 29; one day in ten went above 59.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)100%2,158 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2022	46	21	25	0	0	53	69
2021	365	304	56	5	2	29	186
2020	366	278	78	10	9	29	902
2019	347	256	91	0	0	32	82
2018	336	256	78	2	0	29	135
2017	359	266	86	7	3	29	172
2016	339	306	33	0	0	23	69
2015	365	292	72	1	0	26	141
2014	364	301	63	0	0	27	78
2013	365	260	105	0	0	41	93
2012	362	306	56	0	0	26	73
2011	360	286	74	0	0	27	95
2010	363	316	47	0	0	28	68

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.