Louisiana air quality

Welcome, Louisiana Air Quality

Saint James Parish30.059, -90.868

The nearest monitor to Welcome, at Convent, 5 miles away, measured an index of 32 at Mon, 5:00 PM CDT, which is Good for ground-level ozone. Louisiana Department of Environmental Quality forecasts Moderate for Thibodaux today and Good tomorrow. NOAA’s analysts drew medium wildfire smoke over the town today.

Measured now
32 · Good
Today
51 · Moderate
Tomorrow
48 · Good
Pollutant
Ozone

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Welcome, 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 Welcome, 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 Welcome right now. All Louisiana warnings.

Now

Good

Nearest monitor
Convent, 5 miles away (site 220930002)
Index measured
32 · Good
Measured at
Mon, 5:00 PM CDT
Ozone
31 ppb
Reporting area
Thibodaux, LA, 21 miles away
Reported by
Louisiana Department of Environmental Quality
Area index
50 · Good

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
TodayModerate51Ozone
TomorrowGood48Ozone
Wednesday, September 23Moderate53PM2.5

The forecaster’s discussion

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

Monday, light and variable winds will limit dispersion of pollutants and regional thin smoke. In addition, partly sunny and warm conditions will support ozone formation. Therefore, despite afternoon scattered thunderstorms aiding mixing, AQI levels will be low- to mid-Moderate in most locations. Tuesday, afternoon scattered thunderstorms will aid atmospheric mixing. However, periods of sunshine and warm temperatures will continue to promote ozone formation. Additionally, light easterly to northeasterly winds will allow thin smoke to linger over the region. These conditions will yield high-Good to low-Moderate AQI levels in most cities. Wednesday, as a weak front departs to the south, northeasterly winds will transport regional smoke into the state. Furthermore, increasing sunshine and temperatures in the low- to mid-90s will be conducive for ozone development. Thus, AQI levels will be low- to mid-Moderate in most cities.

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 80, Moderate, around Wed, 9:00 AM CDT, from the run issued Mon, 7:00 AM CDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Mon, 9:00 AM CDT63Moderate15.2
Mon, 10:00 AM CDT58Moderate10.1
Mon, 11:00 AM CDT54Moderate8.7
Mon, 12:00 PM CDT52Moderate8.7
Mon, 1:00 PM CDT48Good8
Mon, 2:00 PM CDT47Good8.3
Mon, 3:00 PM CDT49Good9.135.1
Mon, 4:00 PM CDT52Moderate10.540.5
Mon, 5:00 PM CDT52Moderate1044.2
Mon, 6:00 PM CDT52Moderate9.645.8
Mon, 7:00 PM CDT46Good6.845.5
Mon, 8:00 PM CDT40Good5.144
Mon, 9:00 PM CDT38Good4.441.6
Mon, 10:00 PM CDT35Good538.6
Mon, 11:00 PM CDT33Good6.734.8
Tue, 12:00 AM CDT39Good8.431
Tue, 1:00 AM CDT52Moderate11.927.3
Tue, 2:00 AM CDT56Moderate14.322.9
Tue, 3:00 AM CDT59Moderate15.419.1
Tue, 4:00 AM CDT61Moderate15.715.8
Tue, 5:00 AM CDT64Moderate17.412.8
Tue, 6:00 AM CDT65Moderate17.210
Tue, 7:00 AM CDT65Moderate16.47.8
Tue, 8:00 AM CDT64Moderate15.56.5
Tue, 9:00 AM CDT63Moderate157.1
Tue, 10:00 AM CDT60Moderate12.69.9
Tue, 11:00 AM CDT57Moderate11.114.4
Tue, 12:00 PM CDT55Moderate9.619.5
Tue, 1:00 PM CDT52Moderate8.424.4
Tue, 2:00 PM CDT48Good7.629.4
Tue, 3:00 PM CDT46Good7.833.9
Tue, 4:00 PM CDT46Good8.538
Tue, 5:00 PM CDT47Good8.740.9
Tue, 6:00 PM CDT48Good942.1
Tue, 7:00 PM CDT51Moderate9.741
Tue, 8:00 PM CDT53Moderate11.539.1
Tue, 9:00 PM CDT54Moderate11.737.1
Tue, 10:00 PM CDT56Moderate13.434.4
Tue, 11:00 PM CDT57Moderate13.531.7
Wed, 12:00 AM CDT58Moderate13.628.2
Wed, 1:00 AM CDT59Moderate13.724.4
Wed, 2:00 AM CDT59Moderate1420.3
Wed, 3:00 AM CDT60Moderate14.716.7
Wed, 4:00 AM CDT60Moderate14.313.4
Wed, 5:00 AM CDT62Moderate16.211
Wed, 6:00 AM CDT65Moderate188.9
Wed, 7:00 AM CDT70Moderate22.77.4
Wed, 8:00 AM CDT77Moderate26.86.6
Wed, 9:00 AM CDT80Moderate25.87.5
Wed, 10:00 AM CDT77Moderate21.110.4
Wed, 11:00 AM CDT71Moderate16.615.2
Wed, 12:00 PM CDT64Moderate12.620.3
Wed, 1:00 PM CDT58Moderate10.125
Wed, 2:00 PM CDT55Moderate930
Wed, 3:00 PM CDT52Moderate8.935
Wed, 4:00 PM CDT52Moderate939.7
Wed, 5:00 PM CDT51Moderate9.343.3
Wed, 6:00 PM CDT52Moderate9.944.7
Wed, 7:00 PM CDT53Moderate10.444
Wed, 8:00 PM CDT54Moderate11.842.2
Wed, 9:00 PM CDT56Moderate12.740.3
Wed, 10:00 PM CDT58Moderate13.937
Wed, 11:00 PM CDT59Moderate15.333.3
Thu, 12:00 AM CDT60Moderate14.129.4
Thu, 1:00 AM CDT60Moderate1425.4
Thu, 2:00 AM CDT61Moderate15.521.4
Thu, 3:00 AM CDT62Moderate1617.5
Thu, 4:00 AM CDT64Moderate16.714.5
Thu, 5:00 AM CDT65Moderate17.211.8
Thu, 6:00 AM CDT64Moderate15.510.5
Thu, 7:00 AM CDT62Moderate13.79.6

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 medium smoke over Welcome in satellite imagery today (Mon, 7:00 AM CDT to Mon, 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 0.9 µg/m³ around Tue, 12:00 PM CDT.

Smoke on the radar over Welcome

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 WelcomeWarnings in Saint James ParishLive radar over WelcomeLouisiana 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.