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Union, Iowa

City in Hardin County, Iowa

Air quality

The air at Union

Index 43, good, led by fine particles. Read at 11 PM from its reporting area, Waterloo (IA), 39 miles off.

43Good
  • Fine particles (PM2.5)43Good-

The days ahead

Good each day through Today, led by ozone. Yesterday measured 31, good.

Smoke, the next 44 hours

No smoke near the ground through Sat 7 PM.

FriSat

Precipitation

What has fallen at Union

0.93 in in the last 24 hours, and none in the 2 days before, to Thu 10 PM. Measured by radar and rain gauges, as water.

Last 24 hours
0.93in
Last 3 days
0.93in

Visibility

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

Visibility stays 7 miles or more through Sat 7 PM, lowest 8 miles Sat 4 AM.

FriSat

On the radar over Union, IowaReflectivityStorm topsRain rateRain, last 24 hoursForecast temperatureForecast rain totalEvery picture

What is measuring near here

The 7 instruments nearest Union, 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 now5 instruments

MarshalltownMIW

At an airfield/12.0 mi away/974 ft/23 ft above here

temp, wind, gust, visibility, precip, pressure

Rank8of 1,060

AmesS2031

At a soil climate station/37.5 mi away/1,073 ft/122 ft above here

temp, humidity, soil temp, soil moisture

Rank748of 1,060

Ames ScanAMMI4

At a river or reservoir gauge/37.6 mi away/1,073 ft/122 ft above here

temp, wind, gust, humidity, pressure

Rank720of 1,060

measured daily2 instruments

Conrad 5.2 NWIA-GY-7

In a volunteer observer's own ground/6.7 mi away/1,051 ft/100 ft above here

precip, snowfall, snow depth

Rank-

ZearingZRGI4

At a cooperative observer's station/13.6 mi away/1,056 ft/105 ft above here

snowfall, snow depth, precip, high, low

Rank-

Station report

The weather at Marshalltown, drawn

The nearest airport reporting now, 12.0 mi from Union, Iowa. From its report of Oct 15, 2026, 11:53 PM 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 Marshalltown, 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 MIWFIG. A THE SKY OVER MARSHALLTOWNSECTION, 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 MORE0510TITLEMarshalltown, the skySTATION REPORT · ASOS MIWTYPESECTIONSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 1 of 6DATE2026-10-16IDSR-MIW-1DRAWN AS linework on paperSOURCES FB-SKY-001

The air

46.0 F with a dew point of 39.0 F, 76 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 1,600 ft up.

Chart of the air at Marshalltown: temperature 46.0 degrees Fahrenheit and dew point 39.0, 76 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; height to scale.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT MIWFIG. B THE AIR AT MARSHALLTOWNTHE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALEFT ABOVE THE STATION01,0002,0003,00030 F40 F50 F60 FSATURATES 1,600 FT ABOVE THE STATION, AT 37.5 FTEMPERATURE 46.0 FDEW POINT 39.0 FSPREAD 7.0 FRELATIVE HUMIDITY 76 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 POINTTITLEMarshalltown, the airSTATION REPORT · ASOS MIWTYPECHARTSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 2 of 6DATE2026-10-16IDSR-MIW-2DRAWN AS linework on paperSOURCES FB-WAT-002, FB-ENG-011, FB-ENG-005

The wind

From the northwest (310 degrees) at 14 mph: force 4, a moderate breeze on the Beaufort scale. The strongest gust today was 37 mph.

Plan of the wind at Marshalltown, north up: blowing from 310 degrees, the northwest, at 14 miles an hour; beside it the Beaufort scale from calm to hurricane force, force 4, moderate breeze, marked.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT MIWFIG. C THE WIND AT MARSHALLTOWNPLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALENESWTHE STATIONFROM 310°BEAUFORT FORCELEAST WIND, MPH0CALM01LIGHT AIR12LIGHT BREEZE43GENTLE BREEZE84MODERATE BREEZE13NOW, 14 MPH5FRESH BREEZE196STRONG BREEZE257NEAR GALE328GALE399STRONG GALE4710STORM5511VIOLENT STORM6412HURRICANE FORCE73TITLEMarshalltown, the windSTATION REPORT · ASOS MIWTYPEPLAN north upSCALENOT TO SCALEREVAS REPORTED SHEET 3 of 6DATE2026-10-16IDSR-MIW-3DRAWN AS linework on paperSOURCES FB-EVT-150, FB-ENG-008, FB-INS-002

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

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Snow on the ground

Elsewhere in Iowa

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

Near Union

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

Near Union

River and lake gauges