Louisiana air quality

Saint James Parish, Louisiana Air Quality

Saint James Parish30.026, -90.796

The nearest monitor to Saint James Parish, at Convent, 2 miles away, measured an index of 47 at Tue, 3:00 PM CDT, which is Good for ground-level ozone. Louisiana Department of Environmental Quality forecasts Moderate for Thibodaux today and Moderate tomorrow. NOAA’s analysts drew light wildfire smoke over the town today.

Measured now
47 · Good
Today
71 · Moderate
Tomorrow
53 · Moderate
Pollutant
Ozone

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Saint James Parish, Louisiana. Open it for the live map, where it pans and zooms.

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Saint James Parish, Louisiana Open the live map with the particulate forecast

Map layer from NOAA National Air Quality Forecast Capability. Boundaries from the Iowa Environmental Mesonet.

Alerts in force

An Air Quality Alert is issued by the National Weather Service on behalf of a state or local agency when pollution is expected to reach a level that harms health. An Air Stagnation Advisory means the air will not move enough to clear what is already in it.

None are in force near Saint James Parish right now. All Louisiana warnings.

Now

Good

Nearest monitor
Convent, 2 miles away (site 220930002)
Index measured
47 · Good
Measured at
Tue, 3:00 PM CDT
Ozone
53 ppb
Reporting area
Thibodaux, LA, 18 miles away
Reported by
Louisiana Department of Environmental Quality
Area index
55 · Moderate

Measured, not modeled. AirNow observations are preliminary until the operating agency certifies them, which happens months later.

Today and tomorrow

Louisiana Department of Environmental Quality's own forecast for Thibodaux, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayModerate71Ozone
TomorrowModerate53PM2.5
Thursday, October 1Good45Ozone

The forecaster’s discussion

Written by Louisiana Department of Environmental Quality for Thibodaux and filed with AirNow.

Tuesday, upper-level high pressure will reduce vertical mixing in the atmosphere. In addition, mostly sunny skies and temperatures around 90-95F will enhance ozone development, while calm to light south-southeasterly winds will limit dispersion. Therefore, AQI levels will be high-Moderate in Baton Rouge and New Orleans, with low- to mid-Moderate AQI levels expected elsewhere. Wednesday, southeasterly winds will strengthen, aiding pollutant dispersion in the Bayou State. However, partly to mostly sunny skies and warm temperatures will continue to support ozone production. Thus, AQI levels will be low- to mid-Moderate statewide. Thursday, increasing clouds and scattered thunderstorms in southern Louisiana will reduce ozone production. However, light southeasterly winds will limit pollutant dispersion. These conditions will yield high-Good to low-Moderate AQI levels.

Hour by hour

NOAA’s National Air Quality Forecast Capability, bias-corrected against monitors, for this town’s own coordinate. The worst hour ahead is an index of 90, Moderate, around Tue, 7:00 PM CDT, from the run issued Tue, 7:00 AM CDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Tue, 4:00 PM CDT59Moderate14.954.4
Tue, 5:00 PM CDT71Moderate15.961.7
Tue, 6:00 PM CDT87Moderate15.866.3
Tue, 7:00 PM CDT90Moderate1467.9
Tue, 8:00 PM CDT84Moderate1265.4
Tue, 9:00 PM CDT74Moderate11.862.3
Tue, 10:00 PM CDT61Moderate13.258.2
Tue, 11:00 PM CDT58Moderate1352.9
Wed, 12:00 AM CDT58Moderate12.446
Wed, 1:00 AM CDT58Moderate11.738.4
Wed, 2:00 AM CDT55Moderate10.130.7
Wed, 3:00 AM CDT56Moderate11.824.5
Wed, 4:00 AM CDT55Moderate10.921.3
Wed, 5:00 AM CDT55Moderate11.717.6
Wed, 6:00 AM CDT56Moderate12.613.8
Wed, 7:00 AM CDT56Moderate11.810.9
Wed, 8:00 AM CDT56Moderate12.39.3
Wed, 9:00 AM CDT56Moderate11.19.6
Wed, 10:00 AM CDT53Moderate7.912
Wed, 11:00 AM CDT43Good615.3
Wed, 12:00 PM CDT37Good5.318.6
Wed, 1:00 PM CDT33Good5.222.4
Wed, 2:00 PM CDT29Good4.926.2
Wed, 3:00 PM CDT29Good5.330.1
Wed, 4:00 PM CDT31Good5.134.1
Wed, 5:00 PM CDT33Good4.636.5
Wed, 6:00 PM CDT33Good4.337
Wed, 7:00 PM CDT33Good2.736.7
Wed, 8:00 PM CDT31Good2.834.8
Wed, 9:00 PM CDT31Good533.2
Wed, 10:00 PM CDT29Good5.331.8
Wed, 11:00 PM CDT28Good5.630
Thu, 12:00 AM CDT26Good4.327.3
Thu, 1:00 AM CDT28Good5.324.5
Thu, 2:00 AM CDT27Good4.721.7
Thu, 3:00 AM CDT31Good6.218.5
Thu, 4:00 AM CDT33Good6.316.3
Thu, 5:00 AM CDT32Good5.713.6
Thu, 6:00 AM CDT32Good5.911
Thu, 7:00 AM CDT30Good5.18.7
Thu, 8:00 AM CDT29Good4.97.2
Thu, 9:00 AM CDT28Good4.56.8
Thu, 10:00 AM CDT23Good3.48
Thu, 11:00 AM CDT21Good3.310.5
Thu, 12:00 PM CDT18Good2.713.8
Thu, 1:00 PM CDT16Good2.817.8
Thu, 2:00 PM CDT19Good2.421.7
Thu, 3:00 PM CDT23Good2.625.5
Thu, 4:00 PM CDT27Good4.129.7
Thu, 5:00 PM CDT30Good4.133
Thu, 6:00 PM CDT31Good3.434.5
Thu, 7:00 PM CDT31Good3.334.7
Thu, 8:00 PM CDT31Good3.333.4
Thu, 9:00 PM CDT29Good5.431.5
Thu, 10:00 PM CDT27Good5.229.1
Thu, 11:00 PM CDT28Good5.526.6
Fri, 12:00 AM CDT27Good4.923.8
Fri, 1:00 AM CDT31Good6.121.1
Fri, 2:00 AM CDT29Good518.9
Fri, 3:00 AM CDT33Good6.617
Fri, 4:00 AM CDT35Good6.715.4
Fri, 5:00 AM CDT33Good5.713.6
Fri, 6:00 AM CDT34Good6.412.2
Fri, 7:00 AM CDT32Good5.410.9

Fine particles in micrograms per cubic meter, ozone in parts per billion as an 8-hour average. The index for each hour is EPA’s: the ozone figure is already the 8-hour average the ozone index is defined on, and the particle figure is run through EPA’s NowCast, which is how an hourly PM2.5 concentration becomes an index.

Smoke

NOAA’s Hazard Mapping System analysts drew light smoke over Saint James Parish in satellite imagery today (Tue, 7:00 AM CDT to Tue, 10:00 AM CDT). That is smoke seen from above; it is not always smoke at ground level.

NOAA’s model forecasts near-surface smoke peaking at 1.6 µg/m³ around Tue, 7:00 PM CDT.

Smoke on the radar over Saint James Parish

What this means

Good

Air quality is satisfactory, and air pollution poses little or no risk.

Who is affected
Nobody is expected to be affected.
What to do
It is a good day to be outside.
Index range
0 to 50

Category descriptions are the Environmental Protection Agency’s own.

What these numbers are. An index beside a monitor’s name is a measurement, published hourly by AirNow and preliminary until the operating agency certifies it. A category for today or tomorrow is a state or local agency forecaster’s own forecast for a reporting area. An hourly index is NOAA’s air quality model on a five-kilometer grid, not a reading from any instrument. Where a town has no monitor within reach, only the model figures appear, and the page says so.

Nearby

The nearest towns with a page of their own, closest first.

Weather forecast for Saint James ParishWarnings in Saint James ParishLive radar over Saint James ParishLouisiana air quality

Sources

Observations and daily forecasts from AirNow, the US Environmental Protection Agency’s program with NOAA, the National Park Service, NASA, tribal, state and local agencies. Hourly forecasts from NOAA’s National Air Quality Forecast Capability. Smoke analysis from NOAA’s Hazard Mapping System. Alerts from the National Weather Service. Index categories and breakpoints are EPA’s, as revised in 2024.