Kenai Peninsula, Alaska air quality history

Daily Air Quality Index summaries from EPA monitors in Kenai Peninsula, Alaska, 1988–2025.

100%

Good days in 2024

Median daily AQI, 2024

Days above 100 in 2024

122

Days with an AQI in 2024 (of 366)

In 2024, EPA reported a daily Air Quality Index (AQI) for Kenai Peninsula, Alaska on 122 days. 122 of those days (100%) were in the Good range, and the median daily AQI was 8. That median is lower than the typical monitored county in Alaska (median 24 across 7 counties), and lower than the typical monitored U.S. county (41). The main pollutant was fine particles (PM2.5) on 122 days. Across the years with fuller monitoring, the share of Good days held roughly steady: an average of 98% in 1989–1991 versus 100% in 2021–2024.

EPA did not report an AQI for every day of 2024 here (122 of 366 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

Years with fewer than 120 monitored days (2009, 2015, 2017, 2019, 2023, 2025…) are shown in the table but left out of comparisons and trend statements.

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, 2024

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)	122	100%

Year-by-year data

Annual AQI summary by year
Year	Days with AQI	Good	Moderate	Unhealthy for Sensitive Groups	Unhealthy	Very Unhealthy	Median AQI	90th pct.	Max AQI	Main pollutant
2025	102	102	0	0	0	0	9	16	28	PM2.5
2024	122	122	0	0	0	0	8	17	42	PM2.5
2023	119	119	0	0	0	0	10	16	29	PM2.5
2022	120	119	1	0	0	0	9	21	73	PM2.5
2021	121	121	0	0	0	0	9	19	41	PM2.5
2020	122	120	2	0	0	0	10	19	53	PM2.5
2019	118	111	6	1	0	0	11	28	140	PM2.5
2018	120	120	0	0	0	0	10	21	36	PM2.5
2017	67	67	0	0	0	0	8	16	30	PM2.5
2016	122	122	0	0	0	0	9	18	34	PM2.5
2015	40	40	0	0	0	0	7	14	22	PM2.5
2014	199	179	18	0	2	0	12	51	197	PM2.5
2013	285	276	8	1	0	0	8	30	111	PM10
2012	356	353	3	0	0	0	10	32	89	PM10
2011	166	166	0	0	0	0	11	23	48	PM2.5
2010	121	121	0	0	0	0	7	13	23	PM2.5
2009	117	117	0	0	0	0	8	20	44	PM2.5
2008	118	117	1	0	0	0	7	16	52	PM2.5
2007	108	107	1	0	0	0	7	18	63	PM2.5
2006	118	117	1	0	0	0	8	21	88	PM2.5
2005	113	111	2	0	0	0	8	23	53	PM2.5
2004	115	114	1	0	0	0	7	21	56	PM2.5
2003	113	113	0	0	0	0	7	21	39	PM2.5
2002	97	97	0	0	0	0	8	27	38	PM2.5
2001	5	5	0	0	0	0	4	43	43	PM2.5
1991	172	170	2	0	0	0	7	26	65	NO2
1990	321	311	6	2	1	1	9	26	297	NO2
1989	334	329	2	3	0	0	7	20	119	NO2
1988	37	37	0	0	0	0	2	6	7	PM10

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 Alaska with a similar median AQI in 2024

North Slope

All monitored counties in Alaska

Source: U.S. EPA AirData, “Annual AQI by County” files for 1988–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem