Alamance County, North Carolina air quality history

Daily Air Quality Index summaries from EPA monitors in Alamance, North Carolina, 1993–2015.

67%

Good days in 2015

Median daily AQI, 2015

Days above 100 in 2015

153

Days with an AQI in 2015 (of 365)

In 2015, EPA reported a daily Air Quality Index (AQI) for Alamance, North Carolina on 153 days. 103 of those days (67%) were in the Good range, and the median daily AQI was 42. That median is about the same as the typical monitored county in North Carolina (median 43.5 across 42 counties), and about the same as the typical monitored U.S. county (41). The main pollutant was fine particles (PM2.5) on 153 days. Across the years with fuller monitoring, the share of Good days rose: an average of 25% in 2001–2007 versus 64% in 2013–2015.

EPA did not report an AQI for every day of 2015 here (153 of 365 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.

The most recent year with data for this county is 2015; EPA's files for 2016–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1999, 2000, 2002, 2003, 2004, 2005…) 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, 2015

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)	153	100%

Year-by-year data

Annual AQI summary by year
Year	Days with AQI	Good	Moderate	Unhealthy for Sensitive Groups	Median AQI	90th pct.	Max AQI	Main pollutant
2015	153	103	50	0	42	56	67	PM2.5
2014	365	210	155	0	46	58	76	PM2.5
2013	356	237	119	0	42	57	81	PM2.5
2012	361	195	166	0	49	61	90	PM2.5
2011	365	149	214	2	53	67	108	PM2.5
2010	363	144	219	0	53	66	92	PM2.5
2009	360	153	207	0	53	63	77	PM2.5
2008	359	105	253	1	56	74	138	PM2.5
2007	243	59	179	5	60	81	126	PM2.5
2006	120	26	94	0	56	78	100	PM2.5
2005	118	29	88	1	59	81	110	PM2.5
2004	116	35	80	1	59	76	110	PM2.5
2003	114	38	74	2	57	78	118	PM2.5
2002	116	33	83	0	57	77	98	PM2.5
2001	122	37	82	3	57	76	123	PM2.5
2000	104	18	85	1	61	79	104	PM2.5
1999	99	18	77	4	63	90	120	PM2.5
1997	60	58	2	0	19	34	53	PM10
1996	59	59	0	0	19	33	46	PM10
1995	55	53	2	0	19	32	53	PM10
1994	58	57	1	0	21	35	54	PM10
1993	13	13	0	0	19	27	31	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 North Carolina with a similar median AQI in 2015

All monitored counties in North Carolina

Source: U.S. EPA AirData, “Annual AQI by County” files for 1993–2015 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem