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Penn Valley, California

Community in Nevada County, California

Air quality

The air at Penn Valley

Index 37, good, led by ozone. Read at 10 PM from its reporting area, Western Nevada County (CA), 7 miles off.

37Good
  • Fine particles (PM2.5)-14.1 mi
  • Ozone37Good25 ppb14.1 mi

The days ahead

Yesterday measured 40, good.

Smoke, the next 43 hours

No smoke near the ground through Sat 5 PM.

FriSat

Precipitation

What has fallen at Penn Valley

None in the last 3 days, to Thu 10 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 Penn Valley, the next 43 hours

Visibility stays 10 miles or more through Sat 5 PM.

FriSat

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

What is measuring near here

The 6 instruments nearest Penn Valley, 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

measured daily2 instruments

Penn Valley 0.3 SECA-NV-56

In a volunteer observer's own ground/0.3 mi away/1,436 ft/16 ft above here

precip, snowfall, snow depth

Rank-

Station report

The weather at Grass Valley, drawn

The nearest airport reporting now, 10.4 mi from Penn Valley, California. From its report of Oct 15, 2026, 10:55 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 Grass Valley, 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 GOOFIG. A THE SKY OVER GRASS VALLEYSECTION, 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 MORE0510TITLEGrass Valley, the skySTATION REPORT · ASOS GOOTYPESECTIONSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 1 of 6DATE2026-10-16IDSR-GOO-1DRAWN AS linework on paperSOURCES FB-SKY-001

The air

71.6 F with a dew point of 21.2 F, 15 per cent relative humidity. Air lifted from the station would cool to its dew point, where cloud forms, about 11,200 ft up.

Chart of the air at Grass Valley: temperature 71.6 degrees Fahrenheit and dew point 21.2, 15 per cent relative humidity; air lifted from the station cools along the dry rate and meets its dew point about 11,200 feet above the station; height to scale.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT GOOFIG. B THE AIR AT GRASS VALLEYTHE REPORTED TEMPERATURE AND DEW POINT, AND AIR LIFTED FROM THE STATION WITHOUT MIXING UNTIL IT SATURATES; HEIGHT ABOVE THE STATION TO SCALEFT ABOVE THE STATION02,0004,0006,0008,00010,00012,00014,0000 F20 F40 F60 F80 FSATURATES 11,200 FT ABOVE THE STATION, AT 11.5 FTEMPERATURE 71.6 FDEW POINT 21.2 FSPREAD 50.4 FRELATIVE HUMIDITY 15 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 POINTTITLEGrass Valley, the airSTATION REPORT · ASOS GOOTYPECHARTSCALEHEIGHT TO SCALEREVAS REPORTED SHEET 2 of 6DATE2026-10-16IDSR-GOO-2DRAWN AS linework on paperSOURCES FB-WAT-002, FB-ENG-011, FB-ENG-005

The wind

From the east (90 degrees) at 6 mph, gusting 16 mph: force 2, a light breeze on the Beaufort scale. The strongest gust today was 22 mph.

Plan of the wind at Grass Valley, north up: blowing from 90 degrees, the east, at 6 miles an hour, gusting 16; beside it the Beaufort scale from calm to hurricane force, force 2, light breeze, marked.1122334455667788AABBCCDDEE© 2026 STORM STATION 247THE FIELD BOOKSTATION REPORT GOOFIG. C THE WIND AT GRASS VALLEYPLAN, NORTH UP: THE WIND AS REPORTED, AND WHERE IT SITS ON THE BEAUFORT SCALENESWTHE STATIONFROM 90°BEAUFORT FORCELEAST WIND, MPH0CALM01LIGHT AIR12LIGHT BREEZE4NOW, 6 MPH3GENTLE BREEZE84MODERATE BREEZE13GUST, 16 MPH5FRESH BREEZE196STRONG BREEZE257NEAR GALE328GALE399STRONG GALE4710STORM5511VIOLENT STORM6412HURRICANE FORCE73TITLEGrass Valley, the windSTATION REPORT · ASOS GOOTYPEPLAN north upSCALENOT TO SCALEREVAS REPORTED SHEET 3 of 6DATE2026-10-16IDSR-GOO-3DRAWN AS linework on paperSOURCES FB-EVT-150, FB-ENG-008, FB-INS-002

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

0in

Snow on the ground

Measured at Grass Valley No. 2 (GRAC1), 6.8 miles from here, read 15 Oct, 07:30. measured daily

Elsewhere in California

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

Near Penn Valley

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

Near Penn Valley

River and lake gauges