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Portage Des Sioux, Missouri

City in St. Charles County, Missouri

Air quality

The air at Portage Des Sioux

Index 15, good, led by fine particles. Read at 4 AM from its reporting area, Saint Louis (MO), 28 miles off.

15Good
  • Fine particles (PM2.5)15Good20.8 mi
  • Ozone-19 ppb5.7 mi
  • Coarse particles (PM10)7Good20.6 mi
  • Nitrogen dioxide2Good2.6 ppb7.7 mi
  • Sulfur dioxide0Good0.3 ppb13.4 mi
  • Carbon monoxide-0.2 ppm20.6 mi

The days ahead

Yesterday measured 40, good.

Smoke, the next 45 hours

No smoke near the ground through Sun 1 AM.

FriSat

Precipitation

What has fallen at Portage Des Sioux

0.94 in in the last 24 hours, 1.55 in over the last 3 days, to Fri 3 AM. Measured by radar and rain gauges, as water.

Last 24 hours
0.94in
Last 3 days
1.55in

Visibility

How far you can see at Portage Des Sioux, the next 45 hours

Visibility stays 10 miles or more through Sun 1 AM.

FriSat

On the radar over Portage Des Sioux, MissouriReflectivityStorm topsRain rateRain, last 24 hoursForecast temperatureForecast rain totalEvery picture

What is measuring near here

The 6 instruments nearest Portage Des Sioux, how far away each one is, how high it stands, and what kind of measurement it makes. The nearest is 0.3 miles away.

measured now4 instruments

St. CharlesSCLM7

At a river or reservoir gauge/11.6 mi away/443 ft/7 ft above here

temp, wind, gust, humidity, pressure

Rank651of 1,014

measured daily2 instruments

Portage Des Sioux 0.2 SSEMO-SS-65

In a volunteer observer's own ground/0.3 mi away/435 ft/1 ft below here

precip, snowfall, snow depth

Rank-

Saint CharlesSCHM7

At a cooperative observer's station/12.9 mi away/551 ft/115 ft above here

snowfall, snow depth, precip, high, low

Rank14of 1,014

Station report

The weather at St. Charles, drawn

The nearest airport reporting now, 4.6 mi from Portage Des Sioux, Missouri. From its report of Oct 16, 2026, 4:54 AM local time: 3 of its 6 sheets.

The sky

A few clouds at 2,200 ft, broken at 2,700 ft, broken at 3,500 ft; the ceiling is 2,700 ft; visibility 10 mi or more.

Section of the sky over St. Charles, height above the station to scale: a few clouds cloud with its base at 2,200 feet, broken cloud with its base at 2,700 feet, broken cloud with its base at 3,500 feet, the ceiling at 2,700 feet, and visibility of 10 mi or more.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT SETFIG. A THE SKY OVER ST. CHARLESSECTION, HEIGHT ABOVE THE STATION TO SCALE, EACH LAYER AT THE HEIGHT OF ITS BASE AS REPORTED; COVER IN EIGHTHS OF THE SKY; TOPS NOT MEASUREDFT ABOVE THE STATION01,0002,0003,0004,0005,0006,000ETAGESLOWTHE STATIONTHE CEILOMETER READS TO 12,000 FT, ABOVE THIS SHEETBKN 3,500 FTBROKEN, 5 TO 7 EIGHTHS OF THE SKYBKN 2,700 FTBROKEN, 5 TO 7 EIGHTHS OF THE SKYFEW 2,200 FTA FEW CLOUDS, 1 TO 2 EIGHTHS OF THE SKYCEILING 2,700 FTVISIBILITY, MILES: 10 MI OR MORE0510TITLESt. Charles, the skySTATION REPORT · ASOS SETTYPESECTIONSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 1 of 6DATE2026-10-16IDSR-SET-1DRAWN AS linework on paperSOURCES FB-SKY-001, FB-SKY-017, FB-SKY-016, FB-SKY-018

The air

55.0 F with a dew point of 48.0 F, 77 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 1,600 ft up; the lowest cloud reported is at 2,200 ft.

Chart of the air at St. Charles: temperature 55.0 degrees Fahrenheit and dew point 48.0, 77 per cent relative humidity; air lifted from the station cools along the dry rate and meets its dew point about 1,600 feet above the station, against the lowest cloud reported at 2,200 feet; height to scale.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT SETFIG. B THE AIR AT ST. CHARLESTHE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALEFT ABOVE THE STATION01,0002,0003,00040 F50 F60 F70 FSATURATES 1,600 FT ABOVE THE STATION, AT 46.4 FLOWEST CLOUD REPORTED, FEW 2,200 FTTEMPERATURE 55.0 FDEW POINT 48.0 FSPREAD 7.0 FRELATIVE HUMIDITY 77 PER CENTTHE AIR COOLS ABOUT 5.4 F EACH 1,000 FT IT RISES, AND ITS DEW POINT ABOUT 1 FSOLID: THE LIFTED AIR'S TEMPERATURE; DASHED: ITS DEW POINTTITLESt. Charles, the airSTATION REPORT · ASOS SETTYPECHARTSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 2 of 6DATE2026-10-16IDSR-SET-2DRAWN AS linework on paperSOURCES FB-WAT-002, FB-ENG-011, FB-ENG-005

The wind

From the west northwest (300 degrees) at 20 mph, gusting 28 mph: force 5, a fresh breeze on the Beaufort scale. The strongest gust today was 30 mph.

Plan of the wind at St. Charles, north up: blowing from 300 degrees, the west northwest, at 20 miles an hour, gusting 28; beside it the Beaufort scale from calm to hurricane force, force 5, fresh breeze, marked.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT SETFIG. C THE WIND AT ST. CHARLESPLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALENESWTHE STATIONFROM 300°BEAUFORT FORCELEAST WIND, MPH0CALM01LIGHT AIR12LIGHT BREEZE43GENTLE BREEZE84MODERATE BREEZE135FRESH BREEZE19NOW, 20 MPH6STRONG BREEZE25GUST, 28 MPH7NEAR GALE328GALE399STRONG GALE4710STORM5511VIOLENT STORM6412HURRICANE FORCE73TITLESt. Charles, the windSTATION REPORT · ASOS SETTYPEPLAN north upSCALENOT TO SCALEREVAS REPORTED SHEET 3 of 6DATE2026-10-16IDSR-SET-3DRAWN AS linework on paperSOURCES FB-EVT-150, FB-ENG-008, FB-INS-002

The full report of St. Charles, in 6 sheets, each beside the Field Book plates that explain it

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Snow on the ground

Elsewhere in Missouri

24 places, each with its own forecast and its own instruments.

Near Portage Des Sioux

The nearest places, each with its own forecast and the instruments nearest it.

Near Portage Des Sioux

River and lake gauges