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Thomson, Illinois

Village in Carroll County, Illinois

Air quality

The air at Thomson

Index 20, good, led by ozone. Read at 5 AM from its reporting area, Clinton (IA), 10 miles off.

20Good
  • Fine particles (PM2.5)8Good12 mi
  • Ozone20Good17 ppb8 mi
  • Sulfur dioxide0Good0 ppb12 mi

The days ahead

Yesterday measured 20, good.

Smoke, the next 44 hours

No smoke near the ground through Mon 1 AM.

SatSun

Precipitation

What has fallen at Thomson

0.01 in in the last 24 hours, 0.24 in over the last 3 days, to Sat 5 AM. Measured by radar and rain gauges, as water.

Last 24 hours
0.01in
Last 3 days
0.24in

Visibility

How far you can see at Thomson, the next 44 hours

Visibility stays 10 miles or more through Mon 1 AM.

SatSun

On the radar over Thomson, IllinoisReflectivityStorm topsRain rateRain, last 24 hoursForecast temperatureForecast rain totalEvery picture

What is measuring near here

The 6 instruments nearest Thomson, how far away each one is, how high it stands, and what kind of measurement it makes. The nearest is 4.7 miles away.

measured now4 instruments

SavannaSFY

At an airfield/4.7 mi away/617 ft/11 ft above here

temp, wind, gust, visibility, precip, pressure

Rank360of 1,419

measured daily2 instruments

Dam 13FLTI2

At a dam/4.7 mi away/577 ft/29 ft below here

snowfall, snow depth, precip, high, low

Rank780of 1,419

Savanna 2.6 SSEIL-CR-1

In a volunteer observer's own ground/5.4 mi away/617 ft/11 ft above here

precip, snowfall, snow depth

Rank-

Station report

The weather at Savanna, drawn

The nearest airport reporting now, 4.7 mi from Thomson, Illinois. From its report of Oct 17, 2026, 6:15 AM local time: 3 of its 6 sheets.

The sky

No cloud below 12,000 ft; visibility 10 mi or more.

Section of the sky over Savanna, height above the station to scale: no cloud detected below 12,000 feet, the reach of its ceilometer, and visibility of 10 mi or more.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT SFYFIG. A THE SKY OVER SAVANNASECTION, 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 STATION05001,0001,5002,0002,5003,000ETAGESLOWTHE STATIONTHE CEILOMETER READS TO 12,000 FT, ABOVE THIS SHEETNO CLOUD DETECTED BELOW 12,000 FTVISIBILITY, MILES: 10 MI OR MORE0510TITLESavanna, the skySTATION REPORT · ASOS SFYTYPESECTIONSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 1 of 6DATE2026-10-17IDSR-SFY-1DRAWN AS linework on paperSOURCES FB-SKY-001

The air

31.5 F with a dew point of 30.4 F, 96 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 300 ft up.

Chart of the air at Savanna: temperature 31.5 degrees Fahrenheit and dew point 30.4, 96 per cent relative humidity; air lifted from the station cools along the dry rate and meets its dew point about 300 feet above the station; height to scale.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT SFYFIG. B THE AIR AT SAVANNATHE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALEFT ABOVE THE STATION01,0002,0003,00020 F30 F40 FSATURATES 300 FT ABOVE THE STATION, AT 30.1 FTEMPERATURE AND DEW POINT 31.5 F, 30.4 FRELATIVE HUMIDITY 96 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 POINTTITLESavanna, the airSTATION REPORT · ASOS SFYTYPECHARTSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 2 of 6DATE2026-10-17IDSR-SFY-2DRAWN AS linework on paperSOURCES FB-WAT-020, FB-WAT-002, FB-ENG-011, FB-ENG-005

The wind

Calm.

Plan of the wind at Savanna, north up: calm; beside it the Beaufort scale from calm to hurricane force, force 0, calm, marked.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT SFYFIG. C THE WIND AT SAVANNAPLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALENESWTHE STATIONCALMBEAUFORT FORCELEAST WIND, MPH0CALM0NOW, 0 MPH1LIGHT AIR12LIGHT BREEZE43GENTLE BREEZE84MODERATE BREEZE135FRESH BREEZE196STRONG BREEZE257NEAR GALE328GALE399STRONG GALE4710STORM5511VIOLENT STORM6412HURRICANE FORCE73TITLESavanna, the windSTATION REPORT · ASOS SFYTYPEPLAN north upSCALENOT TO SCALEREVAS REPORTED SHEET 3 of 6DATE2026-10-17IDSR-SFY-3DRAWN AS linework on paperSOURCES FB-EVT-150, FB-ENG-008, FB-INS-002

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

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Snow on the ground

Elsewhere in Illinois

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

Near Thomson

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

Near Thomson

River and lake gauges