Missouri air quality

Spanish Lake, Missouri Air Quality

Saint Louis County38.788, -90.216

The nearest monitor to Spanish Lake, at West Alton, 6 miles away, measured an index of 27 at Sat, 5:00 AM CDT, which is Good for ground-level ozone. Illinois EPA forecasts Good for St. Louis (Metro-east) today and Good tomorrow.

Measured now
27 · Good
Today
— · Good
Tomorrow
— · Good
Pollutant
Ozone

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Spanish Lake, Missouri. Open it for the live map, where it pans and zooms.

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Spanish Lake, Missouri 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 Spanish Lake right now. All Missouri warnings.

Now

Good

Nearest monitor
West Alton, 6 miles away (site 291831002)
Index measured
27 · Good
Measured at
Sat, 5:00 AM CDT
Ozone
29 ppb
Reporting area
St. Louis (Metro-east), IL, 20 miles away
Reported by
Illinois EPA
Area index
28 · Good

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

Today and tomorrow

Illinois EPA's own forecast for St. Louis (Metro-east), written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayGoodPM2.5
TomorrowGoodPM2.5
Monday, September 28GoodPM2.5

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 55, Moderate, around Mon, 11:00 AM CDT, from the run issued Sat, 1:00 AM CDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Sat, 7:00 AM CDT36Good5.3
Sat, 8:00 AM CDT31Good4.5
Sat, 9:00 AM CDT29Good4.912.8
Sat, 10:00 AM CDT29Good5.112.8
Sat, 11:00 AM CDT29Good5.413.1
Sat, 12:00 PM CDT31Good6.213.3
Sat, 1:00 PM CDT33Good6.314.7
Sat, 2:00 PM CDT32Good5.716.4
Sat, 3:00 PM CDT32Good5.718.4
Sat, 4:00 PM CDT31Good5.620.2
Sat, 5:00 PM CDT31Good5.622.2
Sat, 6:00 PM CDT31Good5.224.2
Sat, 7:00 PM CDT32Good6.226.3
Sat, 8:00 PM CDT39Good8.827.4
Sat, 9:00 PM CDT48Good10.226.7
Sat, 10:00 PM CDT48Good8.825.1
Sat, 11:00 PM CDT47Good8.123.6
Sun, 12:00 AM CDT47Good8.722.4
Sun, 1:00 AM CDT46Good8.120.6
Sun, 2:00 AM CDT46Good8.418.3
Sun, 3:00 AM CDT49Good9.515.4
Sun, 4:00 AM CDT51Moderate9.413.5
Sun, 5:00 AM CDT48Good8.312.4
Sun, 6:00 AM CDT44Good6.912
Sun, 7:00 AM CDT44Good7.911.4
Sun, 8:00 AM CDT46Good910.6
Sun, 9:00 AM CDT52Moderate11.110.4
Sun, 10:00 AM CDT52Moderate10.511.2
Sun, 11:00 AM CDT53Moderate10.913.3
Sun, 12:00 PM CDT52Moderate9.216.2
Sun, 1:00 PM CDT51Moderate8.619.9
Sun, 2:00 PM CDT49Good8.223.4
Sun, 3:00 PM CDT47Good7.827.2
Sun, 4:00 PM CDT41Good6.231.4
Sun, 5:00 PM CDT39Good6.735
Sun, 6:00 PM CDT37Good6.237.2
Sun, 7:00 PM CDT37Good6.738.1
Sun, 8:00 PM CDT43Good9.137.5
Sun, 9:00 PM CDT46Good935.5
Sun, 10:00 PM CDT47Good8.833
Sun, 11:00 PM CDT46Good8.230.4
Mon, 12:00 AM CDT46Good8.427.7
Mon, 1:00 AM CDT44Good7.125.1
Mon, 2:00 AM CDT42Good6.922.7
Mon, 3:00 AM CDT41Good720.7
Mon, 4:00 AM CDT41Good7.219.4
Mon, 5:00 AM CDT41Good7.418.7
Mon, 6:00 AM CDT42Good8.317.8
Mon, 7:00 AM CDT48Good10.716.4
Mon, 8:00 AM CDT53Moderate11.614.6
Mon, 9:00 AM CDT53Moderate11.113.7
Mon, 10:00 AM CDT54Moderate11.314
Mon, 11:00 AM CDT55Moderate12.215.4
Mon, 12:00 PM CDT55Moderate11.118.2
Mon, 1:00 PM CDT55Moderate11.121.8
Mon, 2:00 PM CDT54Moderate9.826.3
Mon, 3:00 PM CDT53Moderate9.531.4
Mon, 4:00 PM CDT52Moderate8.937.1
Mon, 5:00 PM CDT52Moderate9.141.6
Mon, 6:00 PM CDT49Good7.745
Mon, 7:00 PM CDT43Good6.746.2
Mon, 8:00 PM CDT44Good8.244.8
Mon, 9:00 PM CDT44Good8.241.9
Mon, 10:00 PM CDT43Good7.438.5
Mon, 11:00 PM CDT44Good8.234.8
Tue, 12:00 AM CDT45Good8.530.8
Tue, 1:00 AM CDT48Good9.826.9

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 analysts have not drawn smoke over Spanish Lake in satellite imagery today.

NOAA’s model forecasts no measurable smoke near the ground here over the next two days.

Smoke on the radar over Spanish Lake

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 Spanish LakeWarnings in Saint Louis CountyLive radar over Spanish LakeMissouri 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.