Arizona air quality

Sierra Vista, Arizona Air Quality

Cochise County31.555, -110.304

The nearest monitor to Sierra Vista, at Paul Spur Chemical Lime Plant, 36 miles away, measured an index of 7 at Tue, 7:00 AM MST, which is Good for coarse particles (PM10). Arizona Department of Environmental Quality forecasts Good for Nogales today and Good tomorrow.

Measured now
7 · Good
Today
41 · Good
Tomorrow
33 · Good
Pollutant
PM10

Fine particles on the map

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

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Sierra Vista, Arizona 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 Sierra Vista right now. All Arizona warnings.

Now

Good

Nearest monitor
Paul Spur Chemical Lime Plant, 36 miles away (site 040030011)
Index measured
7 · Good
Measured at
Tue, 7:00 AM MST
Reporting area
Nogales, AZ, 39 miles away
Reported by
Arizona Department of Environmental Quality
Area index
31 · Good

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

Today and tomorrow

Arizona Department of Environmental Quality's own forecast for Nogales, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayGood41PM2.5
TomorrowGood33PM2.5
Thursday, September 24Good25PM2.5
Friday, September 25Good31PM2.5

The forecaster’s discussion

Written by Arizona Department of Environmental Quality for Nogales and filed with AirNow.

PM10 and PM2.5 levels remained comfortably in the Good AQI range over the weekend. Looking ahead, we don't expect any significant issues. We suspect there has been enough recent rain to minimize the threat of dust. As a result, we are forecasting PM10 and PM2.5 to stay in the Good AQI category through the forecast period.

R. Nicoll

Last Update: Monday, September 21, 2026, 9:15 AM

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 32, Good, around Wed, 5:00 PM MST, from the run issued Mon, 11:00 PM MST. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Tue, 1:00 AM MST30Good5.4
Tue, 2:00 AM MST27Good4.1
Tue, 3:00 AM MST22Good3.1
Tue, 4:00 AM MST19Good3.1
Tue, 5:00 AM MST21Good4.3
Tue, 6:00 AM MST22Good4.3
Tue, 7:00 AM MST23Good4.223.5
Tue, 8:00 AM MST24Good4.623
Tue, 9:00 AM MST22Good3.823.2
Tue, 10:00 AM MST22Good2.624
Tue, 11:00 AM MST22Good2.324.9
Tue, 12:00 PM MST23Good1.925.6
Tue, 1:00 PM MST24Good1.826.1
Tue, 2:00 PM MST25Good1.827.4
Tue, 3:00 PM MST27Good1.829.1
Tue, 4:00 PM MST29Good1.231
Tue, 5:00 PM MST30Good1.632.7
Tue, 6:00 PM MST31Good1.833.4
Tue, 7:00 PM MST31Good2.133.5
Tue, 8:00 PM MST30Good2.332.8
Tue, 9:00 PM MST30Good3.532.1
Tue, 10:00 PM MST29Good331.2
Tue, 11:00 PM MST27Good3.229.9
Wed, 12:00 AM MST26Good428.8
Wed, 1:00 AM MST25Good4.427.4
Wed, 2:00 AM MST23Good3.525.9
Wed, 3:00 AM MST22Good3.624.7
Wed, 4:00 AM MST22Good3.524.1
Wed, 5:00 AM MST22Good4.224.1
Wed, 6:00 AM MST22Good3.924
Wed, 7:00 AM MST22Good4.223.7
Wed, 8:00 AM MST23Good4.423.4
Wed, 9:00 AM MST23Good4.323.8
Wed, 10:00 AM MST22Good3.524.7
Wed, 11:00 AM MST24Good2.726.1
Wed, 12:00 PM MST25Good2.227.7
Wed, 1:00 PM MST27Good2.729.3
Wed, 2:00 PM MST28Good330.9
Wed, 3:00 PM MST30Good2.932.6
Wed, 4:00 PM MST31Good2.434.1
Wed, 5:00 PM MST32Good235.1
Wed, 6:00 PM MST32Good1.935.7
Wed, 7:00 PM MST32Good2.535.4
Wed, 8:00 PM MST31Good3.234.3
Wed, 9:00 PM MST30Good4.432.8
Wed, 10:00 PM MST29Good3.831.2
Wed, 11:00 PM MST27Good4.629.7
Thu, 12:00 AM MST26Good4.628.1
Thu, 1:00 AM MST26Good4.926.5
Thu, 2:00 AM MST24Good4.224.8
Thu, 3:00 AM MST22Good3.623.5
Thu, 4:00 AM MST21Good3.622.8
Thu, 5:00 AM MST23Good4.622.2
Thu, 6:00 AM MST24Good4.621.2
Thu, 7:00 AM MST26Good5.120.1
Thu, 8:00 AM MST25Good4.519.5
Thu, 9:00 AM MST23Good3.420
Thu, 10:00 AM MST19Good2.421.2
Thu, 11:00 AM MST20Good222.9
Thu, 12:00 PM MST22Good1.724.7
Thu, 1:00 PM MST24Good1.726.8
Thu, 2:00 PM MST27Good1.529.1
Thu, 3:00 PM MST29Good1.631.4
Thu, 4:00 PM MST31Good1.433.3
Thu, 5:00 PM MST31Good1.634.7
Thu, 6:00 PM MST32Good2.135.2
Thu, 7:00 PM MST31Good2.634.7
Thu, 8:00 PM MST31Good3.633.7
Thu, 9:00 PM MST30Good5.632.4
Thu, 10:00 PM MST29Good4.931.5
Thu, 11:00 PM MST28Good4.930.7

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 Sierra Vista in satellite imagery today.

NOAA’s model forecasts near-surface smoke peaking at 0.1 µg/m³ around Tue, 1:00 AM MST.

Smoke on the radar over Sierra Vista

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 Sierra VistaWarnings in Cochise CountyLive radar over Sierra VistaArizona 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.