Bad Air Days in Josephine County, Oregon: 17 a Year

17 bad air days a year

Among the worst tenth of monitored US counties. Ranked 41 of 996 monitored counties, where 1 is worst.

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

Which months to watch

Most bad days here fall in August and September. 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 record for Josephine

In 2000 to 2009 this county averaged 2 bad days a year; in 2016 to 2025, 17. It has got worse. The worst recent year was 2018, with 39 bad days on 363 monitored days.

Date	AQI	Main pollutant
2023-08-28	872	PM2.5
2020-09-13	763	PM2.5
2020-09-12	732	PM2.5
2020-09-11	705	PM2.5
2023-08-27	667	PM2.5

Most days, not the worst ones

Across 3,651 monitored days from 2016 to 2025, the air in Josephine County rated Good on 65% of them, less often than the 72% typical of monitored counties, and Moderate on 31%. The median day sat at AQI 38; one day in ten went above 76.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)100%3,651 days

Josephine County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	249	108	8	2	33	208
2024	366	284	74	8	0	29	146
2023	365	205	129	31	21	44	872
2022	365	208	142	15	7	39	252
2021	365	240	106	19	9	36	188
2020	366	228	112	26	22	35	763
2019	365	251	109	5	2	34	175
2018	363	195	129	39	22	47	210
2017	365	219	125	21	16	42	415
2016	366	286	80	0	0	38	87
2015	365	241	118	6	2	37	171
2014	365	264	99	2	0	31	120
2013	365	190	156	19	13	49	450
2012	366	277	89	0	0	31	80
2011	365	261	103	1	0	28	106
2010	365	287	77	1	0	29	103

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

Elsewhere in Oregon

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.