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Monrovia, California

City in Los Angeles County, California

Air quality

The air at Monrovia

Index 41, good, led by ozone. Read at 9 PM from its reporting area, E San Gabriel Vly (CA), 6 miles off.

41Good
  • Fine particles (PM2.5)19Good8.5 mi
  • Ozone41Good22 ppb7.4 mi
  • Coarse particles (PM10)23Good8.5 mi
  • Nitrogen dioxide11Good12.8 ppb7.4 mi
  • Sulfur dioxide0Good0.2 ppb14.2 mi
  • Carbon monoxide-0.7 ppm14.2 mi

The days ahead

Good each day through Sat Oct 17, led by ozone. Yesterday measured 44, good.

Smoke, the next 45 hours

Little smoke near the ground through Sun 5 PM: the index from smoke stays at 22 or under.

SatSun

Precipitation

What has fallen at Monrovia

None in the last 3 days, to Fri 8 PM. Measured by radar and rain gauges, as water.

Last 24 hours
0.00in
Last 3 days
0.00in

Visibility

How far you can see at Monrovia, the next 45 hours

Visibility stays 10 miles or more through Sun 5 PM.

SatSun

On the radar over Monrovia, CaliforniaReflectivityStorm topsRain rateRain, last 24 hoursForecast temperatureForecast rain totalEvery picture

What is measuring near here

The 6 instruments nearest Monrovia, how far away each one is, how high it stands, and what kind of measurement it makes. The nearest is 1.6 miles away.

measured now4 instruments

El MonteEMT

At an airfield/4.5 mi away/295 ft/225 ft below here

temp, wind, gust, visibility, precip, pressure

Rank4,193of 4,461

measured daily2 instruments

Arcadia 1.3 ESECA-LA-142

In a volunteer observer's own ground/1.6 mi away/403 ft/117 ft below here

precip, snowfall, snow depth

Rank-

San Gabriel Canyon PhGABC1

At a cooperative observer's station/5.6 mi away/1,040 ft/520 ft above here

snowfall, snow depth, precip, high, low

Rank-

Station report

The weather at El Monte, drawn

The nearest airport reporting now, 4.5 mi from Monrovia, California. From its report of Oct 16, 2026, 6:45 PM local time: 3 of its 6 sheets.

The sky

Clear; visibility 10 mi or more.

Section of the sky over El Monte, height above the station to scale: a clear sky, and visibility of 10 mi or more.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT EMTFIG. A THE SKY OVER EL MONTESECTION, 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 STATIONCLEARVISIBILITY, MILES: 10 MI OR MORE0510TITLEEl Monte, the skySTATION REPORT · ASOS EMTTYPESECTIONSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 1 of 6DATE2026-10-17IDSR-EMT-1DRAWN AS linework on paperSOURCES FB-SKY-001

The air

89.6 F with a dew point of 37.4 F, 16 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 11,800 ft up.

Chart of the air at El Monte: temperature 89.6 degrees Fahrenheit and dew point 37.4, 16 per cent relative humidity; air lifted from the station cools along the dry rate and meets its dew point about 11,800 feet above the station; height to scale.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT EMTFIG. B THE AIR AT EL MONTETHE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALEFT ABOVE THE STATION02,0004,0006,0008,00010,00012,00014,00020 F40 F60 F80 F100 FSATURATES 11,800 FT ABOVE THE STATION, AT 26.8 FTEMPERATURE 89.6 FDEW POINT 37.4 FSPREAD 52.2 FRELATIVE HUMIDITY 16 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 POINTTITLEEl Monte, the airSTATION REPORT · ASOS EMTTYPECHARTSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 2 of 6DATE2026-10-17IDSR-EMT-2DRAWN AS linework on paperSOURCES FB-WAT-002, FB-ENG-011, FB-ENG-005

The wind

From the northeast (50 degrees) at 8 mph: force 3, a gentle breeze on the Beaufort scale. The strongest gust today was 24 mph.

Plan of the wind at El Monte, north up: blowing from 50 degrees, the northeast, at 8 miles an hour; beside it the Beaufort scale from calm to hurricane force, force 3, gentle breeze, marked.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT EMTFIG. C THE WIND AT EL MONTEPLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALENESWTHE STATIONFROM 50°BEAUFORT FORCELEAST WIND, MPH0CALM01LIGHT AIR12LIGHT BREEZE43GENTLE BREEZE8NOW, 8 MPH4MODERATE BREEZE135FRESH BREEZE196STRONG BREEZE257NEAR GALE328GALE399STRONG GALE4710STORM5511VIOLENT STORM6412HURRICANE FORCE73TITLEEl Monte, the windSTATION REPORT · ASOS EMTTYPEPLAN north upSCALENOT TO SCALEREVAS REPORTED SHEET 3 of 6DATE2026-10-17IDSR-EMT-3DRAWN AS linework on paperSOURCES FB-EVT-150, FB-ENG-008, FB-INS-002

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

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Snow on the ground

Elsewhere in California

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

Near Monrovia

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

Near Monrovia

River and lake gauges