California air quality

Imperial County, California Air Quality

Imperial County33.040, -115.365

The nearest monitor to Imperial County, at Brawley - 220 Main Street, 11 miles away, measured an index of 58 at Fri, 3:00 AM PDT, which is Moderate for coarse particles (PM10). Imperial County Air Pollution Control District forecasts Moderate for Brawley today and Moderate tomorrow.

Measured now
58 · Moderate
Today
71 · Moderate
Tomorrow
67 · Moderate
Pollutant
PM10

Fine particles on the map

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

Now

Moderate

Nearest monitor
Brawley - 220 Main Street, 11 miles away (site 060250007)
Index measured
58 · Moderate
Measured at
Fri, 3:00 AM PDT
Fine particles
9.8 µg/m³
Reporting area
Brawley, CA, 11 miles away
Reported by
Imperial County Air Pollution Control District
Area index
58 · Moderate

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

Today and tomorrow

Imperial County Air Pollution Control District's own forecast for Brawley, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayModerate71Ozone
TomorrowModerate67Ozone
Sunday, September 27Moderate51PM10
Monday, September 28Moderate61PM10
Tuesday, September 29Moderate56PM10

The forecaster’s discussion

Written by Imperial County Air Pollution Control District for Brawley and filed with AirNow.

Today, a weak trough of low pressure aloft will support atmospheric mixing. However, light southerly to easterly winds will limit dispersion and gradually transport regional pollutants into the Imperial Valley, while mostly sunny and hot conditions aid ozone formation. Furthermore, isolated mountain thunderstorms could produce brief blowing dust during the late afternoon and evening. These conditions will result in low-Moderate AQI levels. Tomorrow, as a weak upper-level ridge of high pressure builds over southern California, mixing will decrease slightly. Additionally, sunny skies and temperatures in the low-100s will enhance ozone formation, and calm to light southeasterly winds will lead to pollutant build-up in the Imperial Valley. As a result, AQI 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 52, Moderate, around Fri, 10:00 PM PDT, from the run issued Thu, 11:00 PM PDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Fri, 4:00 AM PDT25Good5.4
Fri, 5:00 AM PDT22Good3.4
Fri, 6:00 AM PDT22Good4
Fri, 7:00 AM PDT21Good3.719.3
Fri, 8:00 AM PDT21Good3.819.2
Fri, 9:00 AM PDT22Good4.119.8
Fri, 10:00 AM PDT19Good321.2
Fri, 11:00 AM PDT26Good5.823.8
Fri, 12:00 PM PDT25Good3.527.1
Fri, 1:00 PM PDT33Good7.930.7
Fri, 2:00 PM PDT32Good5.534.4
Fri, 3:00 PM PDT44Good10.338
Fri, 4:00 PM PDT42Good741.1
Fri, 5:00 PM PDT42Good7.543.2
Fri, 6:00 PM PDT42Good7.545.1
Fri, 7:00 PM PDT42Good4.745.7
Fri, 8:00 PM PDT41Good3.744.8
Fri, 9:00 PM PDT39Good4.242.5
Fri, 10:00 PM PDT52Moderate14.739.6
Fri, 11:00 PM PDT33Good0.736.3
Sat, 12:00 AM PDT31Good1.433.7
Sat, 1:00 AM PDT29Good0.831
Sat, 2:00 AM PDT25Good2.327.3
Sat, 3:00 AM PDT21Good2.323.9
Sat, 4:00 AM PDT19Good3.121.1
Sat, 5:00 AM PDT18Good4.119.6
Sat, 6:00 AM PDT17Good2.418.6
Sat, 7:00 AM PDT18Good3.618.2
Sat, 8:00 AM PDT23Good5.117.2
Sat, 9:00 AM PDT22Good3.917.5
Sat, 10:00 AM PDT22Good4.119.4
Sat, 11:00 AM PDT37Good9.222.7
Sat, 12:00 PM PDT29Good3.926.4
Sat, 1:00 PM PDT34Good7.230.2
Sat, 2:00 PM PDT31Good4.334.3
Sat, 3:00 PM PDT35Good6.638.5
Sat, 4:00 PM PDT39Good4.142.9
Sat, 5:00 PM PDT42Good4.445.7
Sat, 6:00 PM PDT43Good5.846.9
Sat, 7:00 PM PDT43Good2.346.3
Sat, 8:00 PM PDT42Good1.745.1
Sat, 9:00 PM PDT41Good5.744.5
Sat, 10:00 PM PDT49Good13.643
Sat, 11:00 PM PDT38Good3.741.5
Sun, 12:00 AM PDT36Good5.839.9
Sun, 1:00 AM PDT35Good5.638.2
Sun, 2:00 AM PDT37Good7.536.3
Sun, 3:00 AM PDT39Good7.434.9
Sun, 4:00 AM PDT38Good6.834.1
Sun, 5:00 AM PDT39Good7.432.3
Sun, 6:00 AM PDT36Good5.730.4
Sun, 7:00 AM PDT34Good628.3
Sun, 8:00 AM PDT33Good626.2
Sun, 9:00 AM PDT31Good525.1
Sun, 10:00 AM PDT33Good6.625.2
Sun, 11:00 AM PDT34Good6.226.6
Sun, 12:00 PM PDT26Good2.528.5
Sun, 1:00 PM PDT32Good7.231.3
Sun, 2:00 PM PDT32Good3.635.1
Sun, 3:00 PM PDT38Good938.9
Sun, 4:00 PM PDT39Good6.342.7
Sun, 5:00 PM PDT43Good7.246.2
Sun, 6:00 PM PDT45Good849.2
Sun, 7:00 PM PDT46Good6.350.7
Sun, 8:00 PM PDT47Good651.1
Sun, 9:00 PM PDT46Good6.850
Sun, 10:00 PM PDT45Good9.748.1
Sun, 11:00 PM PDT43Good1.646.2

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 Imperial County in satellite imagery today.

NOAA’s model forecasts near-surface smoke peaking at 0.3 µg/m³ around Sat, 10:00 PM PDT.

Smoke on the radar over Imperial County

What this means

Moderate

Air quality is acceptable. There may be a risk for some people, particularly those who are unusually sensitive to air pollution.

Who is affected
People who are unusually sensitive to ozone or fine particles.
What to do
If you are unusually sensitive, consider making long or intense outdoor activity shorter or easier.
Index range
51 to 100

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 Imperial CountyWarnings in Imperial CountyLive radar over Imperial CountyCalifornia 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.