Bad Air Days in Roanoke County, Virginia: under 1 a Year

under 1 bad air days a year

Rare: among the cleanest-air counties EPA monitors. Ranked 824 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 June and July. Averaged over 2016 to 2025.

What actually helps here

Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
On the odd bad day, check AirNow and keep windows shut.

The worst days on file

In 2000 to 2009 this county averaged 14 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2023, with 4 bad days on 365 monitored days.

Date	AQI	Main pollutant
2023-06-29	158	PM2.5
2023-06-28	144	PM2.5
2023-06-30	124	PM2.5
2023-07-17	116	PM2.5
2021-07-21	106	PM2.5

Most days, not the worst ones

Across 3,653 monitored days from 2016 to 2025, the air in Roanoke County rated Good on 75% of them, close to the 72% typical of monitored counties, and Moderate on 25%. The median day sat at AQI 41; one day in ten went above 57.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)61%2,220 days
ozone37%1,334 days
nitrogen dioxide3%96 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	306	59	0	0	37	80
2024	366	306	60	0	0	39	68
2023	365	251	110	4	1	43	158
2022	365	257	108	0	0	42	80
2021	365	246	118	1	0	43	106
2020	366	277	89	0	0	40	72
2019	365	286	79	0	0	42	71
2018	365	265	100	0	0	41	87
2017	365	276	89	0	0	42	80
2016	366	276	90	0	0	41	100
2015	365	242	123	0	0	43	90
2014	365	231	133	1	0	45	108
2013	363	287	76	0	0	37	80
2012	366	310	53	3	0	33	122
2011	365	292	72	1	0	34	112
2010	358	283	69	6	0	37	119

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

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.