Spokane County, Washington air quality history

Daily Air Quality Index summaries from EPA monitors in Spokane, Washington, 1980–2025.

65%

Good days in 2025

Median daily AQI, 2025

Days above 100 in 2025

365

Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Spokane, Washington on 365 days. 236 of those days (65%) were in the Good range, and the median daily AQI was 43. That median is higher than the typical monitored county in Washington (median 28 across 30 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 264 days. Across the years with fuller monitoring, the share of Good days rose: an average of 13% in 1980–1982 versus 71% in 2023–2025.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median daily AQI
90th-percentile daily AQI

Main pollutant by day, 2025

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

Pollutant	Days as main pollutant	Share of monitored days
Fine particles (PM2.5)	264	72%
Ozone	99	27%
Coarse particles (PM10)	2	1%

Year-by-year data

Annual AQI summary by year
Year	Days with AQI	Good	Moderate	Unhealthy for Sensitive Groups	Unhealthy	Very Unhealthy	Hazardous	Median AQI	90th pct.	Max AQI	Main pollutant
2025	365	236	126	3	0	0	0	43	63	126	PM2.5
2024	366	280	85	1	0	0	0	38	62	106	PM2.5
2023	365	257	104	1	1	1	1	42	65	447	PM2.5
2022	365	254	105	3	3	0	0	40	66	185	PM2.5
2021	365	242	114	3	6	0	0	43	67	195	PM2.5
2020	366	286	73	0	1	2	4	36	58	785	PM2.5
2019	365	258	106	1	0	0	0	42	64	107	PM2.5
2018	365	238	115	6	4	2	0	41	74	281	PM2.5
2017	365	227	122	10	2	4	0	43	73	278	PM2.5
2016	366	254	112	0	0	0	0	42	58	81	PM2.5
2015	364	215	135	10	4	0	0	46	71	173	PM2.5
2014	365	230	133	2	0	0	0	42	64	105	PM2.5
2013	365	208	155	1	1	0	0	47	71	175	PM2.5
2012	366	212	152	2	0	0	0	47	67	112	PM2.5
2011	365	227	138	0	0	0	0	45	63	92	PM2.5
2010	365	236	128	1	0	0	0	43	61	103	PM2.5
2009	365	204	161	0	0	0	0	47	62	91	PM2.5
2008	366	206	159	1	0	0	0	46	67	104	PM2.5
2007	365	205	158	2	0	0	0	48	74	105	PM2.5
2006	365	166	192	7	0	0	0	52	77	122	PM2.5
2005	365	160	197	8	0	0	0	52	79	107	PM2.5
2004	366	138	224	4	0	0	0	54	71	115	PM2.5
2003	365	143	206	16	0	0	0	54	84	139	PM2.5
2002	365	144	205	16	0	0	0	53	75	141	PM2.5
2001	365	133	226	5	1	0	0	54	77	153	PM2.5
2000	366	150	207	9	0	0	0	54	77	128	PM2.5
1999	365	212	150	2	1	0	0	47	72	195	PM2.5
1998	365	246	116	3	0	0	0	45	63	112	CO
1997	365	267	96	2	0	0	0	45	60	122	CO
1996	366	231	130	5	0	0	0	46	69	116	CO
1995	365	188	172	4	1	0	0	50	69	161	CO
1994	365	164	199	2	0	0	0	52	77	105	CO
1993	365	140	213	7	4	0	1	56	77	373	CO
1992	366	133	219	12	1	0	1	57	85	721	CO
1991	365	117	230	16	2	0	0	57	92	199	CO
1990	365	101	242	19	3	0	0	59	94	194	CO
1989	365	153	192	17	2	0	1	55	89	370	CO
1988	366	112	208	39	6	1	0	61	113	256	CO
1987	365	102	201	34	20	8	0	66	135	225	CO
1986	365	111	222	24	5	3	0	60	100	204	CO
1985	365	124	197	30	11	3	0	64	109	223	CO
1984	366	122	207	29	5	3	0	59	101	214	CO
1983	365	83	241	33	6	2	0	61	103	207	CO
1982	365	72	239	50	4	0	0	71	111	195	CO
1981	365	46	238	61	19	1	0	77	131	203	CO
1980	366	27	241	68	24	6	0	76	143	226	CO

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

Counties in Washington with a similar median AQI in 2025

All monitored counties in Washington

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem