Ashburn

Data time: 9/18/2025 2:00 AM ET

Hour	AQI	Class	Program	Responsible Pollutant	Activity Caution	Risk Groups
02:00	3	Good	NO2	NO2	None	None
02:00	15	Good	Ozone	Ozone	None	Children and people with asthma are the groups most at risk.
02:00	8	Good	PM10	PM10	None	People with respiratory disease are the group most at risk.
02:00	37	Good	PM2.5	PM2.5	None	People with respiratory or heart disease, the elderly and children are the groups most at risk.
01:00	3	Good	NO2	NO2	None	None
01:00	16	Good	Ozone	Ozone	None	Children and people with asthma are the groups most at risk.
01:00	8	Good	PM10	PM10	None	People with respiratory disease are the group most at risk.
01:00	34	Good	PM2.5	PM2.5	None	People with respiratory or heart disease, the elderly and children are the groups most at risk.
00:00	3	Good	NO2	NO2	None	None
00:00	17	Good	Ozone	Ozone	None	Children and people with asthma are the groups most at risk.
00:00	8	Good	PM10	PM10	None	People with respiratory disease are the group most at risk.
00:00	29	Good	PM2.5	PM2.5	None	People with respiratory or heart disease, the elderly and children are the groups most at risk.
23:00	3	Good	NO2	NO2	None	None
23:00	8	Good	PM10	PM10	None	People with respiratory disease are the group most at risk.
22:00	3	Good	NO2	NO2	None	None
22:00	7	Good	PM10	PM10	None	People with respiratory disease are the group most at risk.
21:00	4	Good	NO2	NO2	None	None
21:00	16	Good	Ozone	Ozone	None	Children and people with asthma are the groups most at risk.