Ozone and PM2.5 Air Quality Index (AQI) Forecast

Issued: Tuesday, July 21, 2026, 2:32 PM

Tuesday, as Tropical Storm Bertha moves westward over the northern Gulf, partly cloudy skies and scattered thunderstorms will hinder ozone development over southeastern Louisiana. However, light to moderate northwesterly winds will continue to transport a thin plume of smoke and Saharan dust over the state, keeping AQI levels low- to mid-Moderate. Wednesday, as Bertha approaches southeastern Louisiana, increasing northeasterly winds will aid dispersion. In addition, partly to mostly cloudy skies and periods of rain will limit ozone formation. However, regional pollutant carryover will allow AQI levels to remain low- to mid-Moderate in most locations. Thursday, light to moderate east-northeasterly winds will gradually transport cleaner air into the state as Bertha continues to progress slowly to the west. Furthermore, areas of clouds and showers will keep ozone development in check. As a result, AQI levels will be Good to low-Moderate.

Baton Rouge

 Tuesday Wednesday Thursday
Ozone 44 - Good 32 - Good 35 - Good
PM25 77 - Moderate 55 - Moderate 53 - Moderate

Alexandria

 Tuesday Wednesday Thursday
Ozone 39 - Good 33 - Good 30 - Good
PM25 69 - Moderate 66 - Moderate 50 - Good

Lake Charles

 Tuesday Wednesday Thursday
Ozone 33 - Good 41 - Good 28 - Good
PM25 64 - Moderate 73 - Moderate 50 - Good

Lafayette

 Tuesday Wednesday Thursday
Ozone 32 - Good 31 - Good 32 - Good
PM25 66 - Moderate 64 - Moderate 39 - Good

Monroe

 Tuesday Wednesday Thursday
Ozone 40 - Good 34 - Good 29 - Good
PM25 77 - Moderate 71 - Moderate 53 - Moderate

New Orleans

 Tuesday Wednesday Thursday
Ozone 32 - Good 33 - Good 34 - Good
PM25 62 - Moderate 50 - Good 53 - Moderate

Shreveport

 Tuesday Wednesday Thursday
Ozone 43 - Good 37 - Good 31 - Good
PM25 73 - Moderate 71 - Moderate 62 - Moderate

Thibodaux

 Tuesday Wednesday Thursday
Ozone 44 - Good 34 - Good 33 - Good
PM25 71 - Moderate 56 - Moderate 50 - Good

More Information About Understanding AQI Information

The AQI is an index for reporting daily air quality. It tells you how clean or unhealthy your air is, and what associated health effects might be a concern. The AQI focuses on health effects you may experience within a few hours or days after breathing unhealthy air. The following chart provides information regarding the AQI determinations:

Category AQI Value What This Means
Good 0-50 Air quality is considered satisfactory, and air pollution poses little or no risk.
Moderate 51-100 Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
Unhealthy for Sensitive Groups 101-150 Members of sensitive groups may experience health effects. The general public is not likely to be affected.
Unhealthy 151-200 Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.
Very Unhealthy 201-300 Health warnings of emergency conditions. The entire population is more likely to be affected.
Hazardous 301-500 Health alert: everyone may experience more serious health effects.

Any questions about interpreting this monitoring data should be directed to the DEQ Customer Services Section at 1-866-896-5337.

TO REPORT ENVIRONMENTAL CONCERNS, INCLUDING ODORS, CONTACT THE DEQ SINGLE POINT OF CONTACT (SPOC) - 225-219-3640 or Toll Free 1-888-763-5424. In the event of an environmental emergency, citizens are encouraged to first contact their local authorities - police, sheriff, fire department, etc. Otherwise citizens and the regulated community can contact the SPOC line to report environmental concerns during business hours, 8 a.m. - 4:30 p.m., Monday through Friday at the number listed above. To report a concern outside of business hours call 225-342-1234 or the toll free number. Concerns include spills, releases, odors, fish kills, open burning, waste tires and any other types of environmental incidents. Citizens can report the incident online.

The data has not been quality reviewed or validated. Continuous PM2.5 readings shown are not NAAQS comparable.