North Carolina air quality

Guilford County, North Carolina Air Quality

Guilford County36.080, -79.789

The nearest monitor to Guilford County, at MENDNHAL, 2 miles away, measured an index of 29 at Sat, 9:00 AM EDT, which is Good for ground-level ozone. Forsyth County Office of Environmental Assistance and Protection forecasts Good for Forsyth County-Winston-Salem-Greensboro-High Point today and Good tomorrow.

Measured now
29 · Good
Today
42 · Good
Tomorrow
40 · Good
Pollutant
Ozone

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Guilford County, North Carolina. Open it for the live map, where it pans and zooms.

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Guilford County, North Carolina 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 Guilford County right now. All North Carolina warnings.

Now

Good

Nearest monitor
MENDNHAL, 2 miles away (site 370810013)
Index measured
29 · Good
Measured at
Sat, 9:00 AM EDT
Fine particles
2.9 µg/m³
Ozone
33 ppb
Reporting area
Forsyth County-Winston-Salem-Greensboro-High Point, NC, 20 miles away
Reported by
Forsyth County Office of Environmental Assistance and Protection
Area index
31 · Good

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

Today and tomorrow

Forsyth County Office of Environmental Assistance and Protection's own forecast for Forsyth County-Winston-Salem-Greensboro-High Point, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayGood42Ozone
TomorrowGood40Ozone
Monday, September 28Good46Ozone
Tuesday, September 29Good50Ozone

The forecaster’s discussion

Written by Forsyth County Office of Environmental Assistance and Protection for Forsyth County-Winston-Salem-Greensboro-High Point and filed with AirNow.

Air quality levels remain GOOD and code GREEN, Saturday. High pressure has settled over the state and will dominate the weather through the forecast period. Skies will be clear and sunny as high temperatures climb to near 80, Sunday, Monday, and Tuesday. Winds on Sunday and Monday will be from a relatively clean NW direction, helping the AQI stay in the code GREEN category. By Tuesday, winds will begin to decrease, leading to a slight uptick in ozone production and air mass stagnation. While particle pollution looks to be well within the code GREEN range, Tuesday, ozone will be higher and upper code GREEN or low code YELLOW (GENTRY; gentrycd@forsyth.cc).

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 50, Good, around Sun, 7:00 AM EDT, from the run issued Sat, 2:00 AM EDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Sat, 11:00 AM EDT26Good3.711.8
Sat, 12:00 PM EDT19Good2.314.1
Sat, 1:00 PM EDT19Good3.517.6
Sat, 2:00 PM EDT19Good2.521.9
Sat, 3:00 PM EDT24Good0.926.2
Sat, 4:00 PM EDT28Good2.530.6
Sat, 5:00 PM EDT31Good3.834.2
Sat, 6:00 PM EDT33Good2.136.9
Sat, 7:00 PM EDT35Good2.938.1
Sat, 8:00 PM EDT34Good3.437.5
Sat, 9:00 PM EDT32Good6.235.3
Sat, 10:00 PM EDT30Good2.832.6
Sat, 11:00 PM EDT28Good4.530.3
Sun, 12:00 AM EDT27Good5.728.2
Sun, 1:00 AM EDT25Good4.326.3
Sun, 2:00 AM EDT28Good5.824.3
Sun, 3:00 AM EDT29Good5.522.2
Sun, 4:00 AM EDT33Good6.720.9
Sun, 5:00 AM EDT36Good720.2
Sun, 6:00 AM EDT38Good7.519.2
Sun, 7:00 AM EDT50Good11.118.4
Sun, 8:00 AM EDT41Good5.917.5
Sun, 9:00 AM EDT42Good7.716.9
Sun, 10:00 AM EDT46Good9.217.1
Sun, 11:00 AM EDT41Good6.418.9
Sun, 12:00 PM EDT34Good4.922
Sun, 1:00 PM EDT32Good5.526.1
Sun, 2:00 PM EDT29Good4.630.8
Sun, 3:00 PM EDT31Good3.534.8
Sun, 4:00 PM EDT35Good5.638.8
Sun, 5:00 PM EDT39Good642.4
Sun, 6:00 PM EDT42Good2.745.3
Sun, 7:00 PM EDT44Good4.247.1
Sun, 8:00 PM EDT43Good1.946.4
Sun, 9:00 PM EDT41Good4.744.6
Sun, 10:00 PM EDT38Good3.741.5
Sun, 11:00 PM EDT34Good5.738
Mon, 12:00 AM EDT31Good6.534
Mon, 1:00 AM EDT28Good4.330.2
Mon, 2:00 AM EDT33Good726.6
Mon, 3:00 AM EDT36Good7.123.6
Mon, 4:00 AM EDT35Good6.122.8
Mon, 5:00 AM EDT30Good4.622.4
Mon, 6:00 AM EDT32Good6.222.4
Mon, 7:00 AM EDT43Good9.722.5
Mon, 8:00 AM EDT37Good5.523
Mon, 9:00 AM EDT33Good5.423.7
Mon, 10:00 AM EDT40Good8.524.7
Mon, 11:00 AM EDT32Good4.425.9
Mon, 12:00 PM EDT29Good4.727.2
Mon, 1:00 PM EDT31Good6.129.1
Mon, 2:00 PM EDT29Good4.231.1
Mon, 3:00 PM EDT31Good4.333.7
Mon, 4:00 PM EDT33Good4.236.1
Mon, 5:00 PM EDT35Good6.438.4
Mon, 6:00 PM EDT36Good539.9
Mon, 7:00 PM EDT37Good3.940.3
Mon, 8:00 PM EDT35Good4.139
Mon, 9:00 PM EDT33Good5.436.6
Mon, 10:00 PM EDT31Good5.934.5
Mon, 11:00 PM EDT30Good4.932.2
Tue, 12:00 AM EDT32Good6.929.6
Tue, 1:00 AM EDT34Good6.426.7
Tue, 2:00 AM EDT34Good6.524.9

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 Guilford County in satellite imagery today.

NOAA’s model forecasts near-surface smoke peaking at 0.1 µg/m³ around Sat, 7:00 PM EDT.

Smoke on the radar over Guilford County

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 Guilford CountyWarnings in Guilford CountyLive radar over Guilford CountyNorth Carolina 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.