Bad Air Days in Orange County, Texas: 2 a Year

2 bad air days a year

Fewer bad air days than most monitored US counties. Ranked 585 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (20% particle days).

When the bad days come in Orange

Most bad days here fall in May and June and April 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.

Better or worse than it was

In 2000 to 2009 this county averaged 15 bad days a year; in 2016 to 2025, 2. The air has improved. The worst recent year was 2018, with 6 bad days on 365 monitored days.

Date	AQI	Main pollutant
2018-07-27	122	Ozone
2024-05-15	119	Ozone
2018-04-25	115	Ozone
2018-05-08	108	Ozone
2018-05-16	108	Ozone

The air on a normal day

Across 3,637 monitored days from 2016 to 2025, the air in Orange County rated Good on 64% of them, less often than the 72% typical of monitored counties, and Moderate on 36%. The median day sat at AQI 44; one day in ten went above 60.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)67%2,427 days
ozone33%1,199 days

Orange County by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	364	219	145	0	0	45	90
2024	366	238	125	3	0	44	119
2023	365	213	151	1	0	46	101
2022	365	247	116	2	0	43	108
2021	364	262	102	0	0	41	80
2020	362	223	137	2	0	44	103
2019	365	233	132	0	0	44	100
2018	365	173	186	6	0	52	122
2017	355	221	133	1	0	43	105
2016	366	283	83	0	0	39	87
2015	365	252	113	0	0	42	100
2014	365	232	130	3	0	43	129
2013	365	233	131	1	0	46	129
2012	366	221	140	5	0	46	147
2011	365	208	147	10	1	47	154
2010	365	162	189	14	0	52	136

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

Texas compared

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, and on why a purifier does not touch ozone in smoke vs ozone.