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Knightsen, California

Community in Contra Costa County, California

Air quality

The air at Knightsen

Index 61, moderate, led by coarse particles. Read at 8 PM from its reporting area, Stockton (CA), 19 miles off.

61Moderate
  • Fine particles (PM2.5)56Moderate-
  • Ozone44Good35 ppb3.2 mi
  • Coarse particles (PM10)61Moderate-
  • Nitrogen dioxide5Good5.5 ppb3.2 mi
  • Sulfur dioxide1Good1.3 ppb3.2 mi
  • Carbon monoxide-0.4 ppm3.2 mi

The days ahead

Moderate each day through Fri Oct 16, led by fine particles. Yesterday measured 50, good.

Smoke, the next 45 hours

Little smoke near the ground through Sat 5 PM: the index from smoke stays at 17 or under.

FriSat

Precipitation

What has fallen at Knightsen

None in the last 3 days, to Thu 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 Knightsen, the next 45 hours

Visibility stays 10 miles or more through Sat 5 PM.

FriSat

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

What is measuring near here

The 6 instruments nearest Knightsen, how far away each one is, how high it stands, and what kind of measurement it makes. The nearest is 3.7 miles away.

measured now4 instruments

ByronC83

At an airfield/9.2 mi away/52 ft/28 ft above here

temp, wind, gust, visibility, precip, pressure

Rank589of 4,465

measured daily2 instruments

Station report

The weather at Byron, drawn

The nearest airport reporting now, 9.2 mi from Knightsen, California. From its report of Oct 15, 2026, 9:20 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 Byron, 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 C83FIG. A THE SKY OVER BYRONSECTION, 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 MORE0510TITLEByron, the skySTATION REPORT · ASOS C83TYPESECTIONSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 1 of 6DATE2026-10-16IDSR-C83-1DRAWN AS linework on paperSOURCES FB-SKY-001

The air

66.2 F with a dew point of 33.8 F, 30 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 7,300 ft up.

Chart of the air at Byron: temperature 66.2 degrees Fahrenheit and dew point 33.8, 30 per cent relative humidity; air lifted from the station cools along the dry rate and meets its dew point about 7,300 feet above the station; height to scale.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT C83FIG. B THE AIR AT BYRONTHE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALEFT ABOVE THE STATION02,0004,0006,0008,00010,00020 F30 F40 F50 F60 F70 F80 FSATURATES 7,300 FT ABOVE THE STATION, AT 27.1 FTEMPERATURE 66.2 FDEW POINT 33.8 FSPREAD 32.4 FRELATIVE HUMIDITY 30 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 POINTTITLEByron, the airSTATION REPORT · ASOS C83TYPECHARTSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 2 of 6DATE2026-10-16IDSR-C83-2DRAWN AS linework on paperSOURCES FB-WAT-002, FB-ENG-011, FB-ENG-005

The wind

From the west southwest (240 degrees) at 6 mph: force 2, a light breeze on the Beaufort scale.

Plan of the wind at Byron, north up: blowing from 240 degrees, the west southwest, at 6 miles an hour; beside it the Beaufort scale from calm to hurricane force, force 2, light breeze, marked.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT C83FIG. C THE WIND AT BYRONPLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALENESWTHE STATIONFROM 240°BEAUFORT FORCELEAST WIND, MPH0CALM01LIGHT AIR12LIGHT BREEZE4NOW, 6 MPH3GENTLE BREEZE84MODERATE BREEZE135FRESH BREEZE196STRONG BREEZE257NEAR GALE328GALE399STRONG GALE4710STORM5511VIOLENT STORM6412HURRICANE FORCE73TITLEByron, the windSTATION REPORT · ASOS C83TYPEPLAN north upSCALENOT TO SCALEREVAS REPORTED SHEET 3 of 6DATE2026-10-16IDSR-C83-3DRAWN AS linework on paperSOURCES FB-EVT-150, FB-ENG-008, FB-INS-002

The full report of Byron, 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 Knightsen

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

Near Knightsen

River and lake gauges