Bad Air Days in St. Bernard Parish, Louisiana: 1 a Year
1 bad air day a year
Fewer bad air days than most monitored US counties. Ranked 654 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (18% particle days).
Which months to watch
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in May and June. Averaged over 2016 to 2025.
What to buy, and what not to
- 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 12 bad days a year; in 2016 to 2025, 1. The air has improved. The worst recent year was 2018, with 3 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2024-01-01 | 138 | PM2.5 |
| 2023-06-09 | 119 | Ozone |
| 2016-07-02 | 115 | Ozone |
| 2018-05-09 | 112 | Ozone |
| 2018-05-17 | 112 | Ozone |
An ordinary day in St. Bernard
Across 3,638 monitored days from 2016 to 2025, the air in St. Bernard Parish rated Good on 58% of them, less often than the 72% typical of monitored counties, and Moderate on 41%. The median day sat at AQI 47; one day in ten went above 61.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)62%2,247 days
- ozone38%1,388 days
St. Bernard Parish by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 266 | 99 | 0 | 0 | 44 | 93 |
| 2024 | 366 | 241 | 123 | 2 | 0 | 45 | 138 |
| 2023 | 365 | 156 | 207 | 2 | 0 | 52 | 119 |
| 2022 | 365 | 209 | 155 | 1 | 0 | 47 | 108 |
| 2021 | 359 | 206 | 153 | 0 | 0 | 47 | 80 |
| 2020 | 357 | 229 | 128 | 0 | 0 | 44 | 86 |
| 2019 | 365 | 159 | 205 | 1 | 0 | 52 | 112 |
| 2018 | 365 | 188 | 174 | 3 | 0 | 49 | 112 |
| 2017 | 365 | 259 | 106 | 0 | 0 | 43 | 99 |
| 2016 | 366 | 210 | 154 | 2 | 0 | 46 | 115 |
| 2015 | 365 | 164 | 201 | 0 | 0 | 52 | 94 |
| 2014 | 364 | 145 | 214 | 5 | 0 | 53 | 112 |
| 2013 | 358 | 227 | 130 | 1 | 0 | 45 | 115 |
| 2012 | 359 | 120 | 238 | 1 | 0 | 55 | 119 |
| 2011 | 362 | 96 | 259 | 7 | 0 | 58 | 143 |
| 2010 | 365 | 82 | 275 | 8 | 0 | 58 | 140 |
*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, and on why a purifier does not touch ozone in smoke vs ozone.