California air quality

Granite Bay, California Air Quality

Placer County38.763, -121.164

The nearest monitor to Granite Bay, at Folsom, 6 miles away, measured an index of 27 at Tue, 7:00 AM PDT, which is Good for fine particles (PM2.5). Placer County APCD forecasts Moderate for Roseville-Rocklin today and Moderate tomorrow.

Measured now
27 · Good
Today
64 · Moderate
Tomorrow
77 · Moderate
Pollutant
PM2.5

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Granite Bay, California. Open it for the live map, where it pans and zooms.

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Granite Bay, California Open the live map with the particulate forecast

Map layer from NOAA National Air Quality Forecast Capability. Boundaries from the Iowa Environmental Mesonet.

Alerts in force

An Air Quality Alert is issued by the National Weather Service on behalf of a state or local agency when pollution is expected to reach a level that harms health. An Air Stagnation Advisory means the air will not move enough to clear what is already in it.

None are in force near Granite Bay right now. All California warnings.

Now

Good

Nearest monitor
Folsom, 6 miles away (site 060670012)
Index measured
27 · Good
Measured at
Tue, 7:00 AM PDT
Fine particles
7 µg/m³
Ozone
20 ppb
Reporting area
Roseville-Rocklin, CA, 5 miles away
Reported by
Placer County APCD
Area index
29 · Good

Measured, not modeled. AirNow observations are preliminary until the operating agency certifies them, which happens months later.

Today and tomorrow

Placer County APCD's own forecast for Roseville-Rocklin, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayModerate64Ozone
TomorrowModerate77Ozone
Thursday, September 24Moderate87Ozone
Friday, September 25Moderate58Ozone
Saturday, September 26Good50Ozone

The forecaster’s discussion

Written by Placer County APCD for Roseville-Rocklin and filed with AirNow.

Monday, mostly sunny skies will support ozone formation in the Sacramento region. However, high temperatures in the low-80s will limit ozone production. In addition, light to moderate onshore winds will develop through the afternoon, dispersing pollutants and leading to low-Moderate ozone levels. Tuesday, lighter winds will allow pollutants to accumulate in the Sacramento region. Furthermore, mostly sunny skies with temperatures in the mid-80s will increase ozone production slightly, yielding mid-Moderate ozone levels. Wednesday, winds will remain light in the Sacramento region, limiting dispersion and leading to pollutant build-up. Furthermore, a weak upper-level ridge of high pressure will produce sunny skies and surface temperatures in the low-90s, enhancing ground-level ozone formation. As a result, ozone levels will be mid-Moderate.

Hour by hour

NOAA’s National Air Quality Forecast Capability, bias-corrected against monitors, for this town’s own coordinate. The worst hour ahead is an index of 55, Moderate, around Tue, 10:00 PM PDT, from the run issued Mon, 11:00 PM PDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Tue, 1:00 AM PDT42Good7.6
Tue, 2:00 AM PDT41Good7.1
Tue, 3:00 AM PDT39Good6.3
Tue, 4:00 AM PDT33Good4.7
Tue, 5:00 AM PDT28Good4.3
Tue, 6:00 AM PDT29Good5.3
Tue, 7:00 AM PDT28Good523.2
Tue, 8:00 AM PDT26Good4.222.5
Tue, 9:00 AM PDT22Good3.422.3
Tue, 10:00 AM PDT23Good4.322.6
Tue, 11:00 AM PDT26Good5.223.4
Tue, 12:00 PM PDT26Good4.925
Tue, 1:00 PM PDT27Good527
Tue, 2:00 PM PDT27Good4.729.3
Tue, 3:00 PM PDT30Good6.232
Tue, 4:00 PM PDT32Good635.5
Tue, 5:00 PM PDT36Good7.439.3
Tue, 6:00 PM PDT42Good8.543.2
Tue, 7:00 PM PDT43Good846.5
Tue, 8:00 PM PDT48Good9.848.3
Tue, 9:00 PM PDT53Moderate1248.6
Tue, 10:00 PM PDT55Moderate11.848
Tue, 11:00 PM PDT54Moderate10.146.8
Wed, 12:00 AM PDT52Moderate8.444.8
Wed, 1:00 AM PDT51Moderate9.241.9
Wed, 2:00 AM PDT48Good838.3
Wed, 3:00 AM PDT43Good7.134.7
Wed, 4:00 AM PDT42Good6.931.9
Wed, 5:00 AM PDT38Good6.330.2
Wed, 6:00 AM PDT39Good7.328.9
Wed, 7:00 AM PDT40Good7.427.5
Wed, 8:00 AM PDT39Good7.126.5
Wed, 9:00 AM PDT39Good6.925.9
Wed, 10:00 AM PDT38Good6.526.2
Wed, 11:00 AM PDT39Good7.627.7
Wed, 12:00 PM PDT39Good7.330.3
Wed, 1:00 PM PDT40Good7.733.2
Wed, 2:00 PM PDT42Good8.336.6
Wed, 3:00 PM PDT43Good8.540.3
Wed, 4:00 PM PDT42Good744.1
Wed, 5:00 PM PDT44Good7.447.9
Wed, 6:00 PM PDT47Good8.251.5
Wed, 7:00 PM PDT49Good7.553.8
Wed, 8:00 PM PDT49Good10.753.9
Wed, 9:00 PM PDT55Moderate12.953
Wed, 10:00 PM PDT55Moderate11.651.5
Wed, 11:00 PM PDT52Moderate8.449.7
Thu, 12:00 AM PDT50Good847.5
Thu, 1:00 AM PDT46Good7.544.9
Thu, 2:00 AM PDT39Good6.141.7
Thu, 3:00 AM PDT38Good6.738.3
Thu, 4:00 AM PDT36Good6.136.1
Thu, 5:00 AM PDT34Good5.734.6
Thu, 6:00 AM PDT38Good7.533.2
Thu, 7:00 AM PDT35Good631.9
Thu, 8:00 AM PDT32Good5.330.8
Thu, 9:00 AM PDT31Good5.430.1
Thu, 10:00 AM PDT32Good5.730.4
Thu, 11:00 AM PDT36Good7.931.9
Thu, 12:00 PM PDT43Good9.334.6
Thu, 1:00 PM PDT47Good9.237.8
Thu, 2:00 PM PDT49Good9.641.5
Thu, 3:00 PM PDT50Good9.145.2
Thu, 4:00 PM PDT47Good7.748.9
Thu, 5:00 PM PDT47Good7.651.7
Thu, 6:00 PM PDT48Good5.552.9
Thu, 7:00 PM PDT48Good4.752.5
Thu, 8:00 PM PDT46Good5.450.6
Thu, 9:00 PM PDT44Good5.547.9
Thu, 10:00 PM PDT41Good544.8
Thu, 11:00 PM PDT38Good4.641.2

Fine particles in micrograms per cubic meter, ozone in parts per billion as an 8-hour average. The index for each hour is EPA’s: the ozone figure is already the 8-hour average the ozone index is defined on, and the particle figure is run through EPA’s NowCast, which is how an hourly PM2.5 concentration becomes an index.

Smoke

NOAA’s analysts have not drawn smoke over Granite Bay in satellite imagery today.

NOAA’s model forecasts near-surface smoke peaking at 2.1 µg/m³ around Wed, 8:00 AM PDT.

Smoke on the radar over Granite Bay

What this means

Good

Air quality is satisfactory, and air pollution poses little or no risk.

Who is affected
Nobody is expected to be affected.
What to do
It is a good day to be outside.
Index range
0 to 50

Category descriptions are the Environmental Protection Agency’s own.

What these numbers are. An index beside a monitor’s name is a measurement, published hourly by AirNow and preliminary until the operating agency certifies it. A category for today or tomorrow is a state or local agency forecaster’s own forecast for a reporting area. An hourly index is NOAA’s air quality model on a five-kilometer grid, not a reading from any instrument. Where a town has no monitor within reach, only the model figures appear, and the page says so.

Nearby

The nearest towns with a page of their own, closest first.

Weather forecast for Granite BayWarnings in Placer CountyLive radar over Granite BayCalifornia air quality

Sources

Observations and daily forecasts from AirNow, the US Environmental Protection Agency’s program with NOAA, the National Park Service, NASA, tribal, state and local agencies. Hourly forecasts from NOAA’s National Air Quality Forecast Capability. Smoke analysis from NOAA’s Hazard Mapping System. Alerts from the National Weather Service. Index categories and breakpoints are EPA’s, as revised in 2024.