Arizona air quality

Tempe Junction, Arizona Air Quality

Maricopa County33.414, -111.943

The nearest monitor to Tempe Junction, at Tempe, under a mile away, measured an index of 31 at Sun, 4:00 PM MST, which is Good for ground-level ozone. Arizona Department of Environmental Quality forecasts Moderate for Phoenix today and Moderate tomorrow.

Measured now
31 · Good
Today
58 · Moderate
Tomorrow
54 · Moderate
Pollutant
Ozone

Fine particles on the map

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

Now

Good

Nearest monitor
Tempe, under a mile away (site 040134005)
Index measured
31 · Good
Measured at
Sun, 4:00 PM MST
Fine particles
4.2 µg/m³
Ozone
37 ppb
Reporting area
Phoenix, AZ, 12 miles away
Reported by
Arizona Department of Environmental Quality
Area index
40 · 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 Phoenix, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayModerate58Ozone
TomorrowModerate54Ozone
Tuesday, September 22Good49Ozone

The forecaster’s discussion

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

Clear skies are the highlight of the morning. With the next area of low pressure moving in today, the forecast holds daily ozone in the Good AQI category for one more day. After, enough sunshine is expected into the weekend to bump daily ozone levels to the Moderate AQI category. Daily ozone levels Monday could also reach the lower Moderate AQI category, although it is forecast to be on the downtrend as low pressure is forecast and will also bring more cloud cover. Daily ozone on Tuesday is forecast to be in the Good AQI range.

For PM10, the main factors in recent days (thunderstorms and outflow winds) are at bay. Overall, PM10 is forecast to be in the Good AQI category the next several days. The typical short-lived increases (mainly in the mornings) from industrial and construction activity is expected, especially in western Phoenix. PM2.5 will hold similar trends.

A. Hermansen

Last Update: Friday, September 18, 2026, 9:17 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 51, Moderate, around Sun, 11:00 PM MST, from the run issued Sun, 5:00 AM MST. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Sun, 7:00 AM MST26Good4.1
Sun, 8:00 AM MST26Good4.5
Sun, 9:00 AM MST24Good4
Sun, 10:00 AM MST23Good3.8
Sun, 11:00 AM MST21Good3.3
Sun, 12:00 PM MST17Good2.5
Sun, 1:00 PM MST23Good2.725.6
Sun, 2:00 PM MST28Good2.830.3
Sun, 3:00 PM MST31Good2.834.7
Sun, 4:00 PM MST35Good2.438
Sun, 5:00 PM MST37Good2.840.3
Sun, 6:00 PM MST38Good1.841.4
Sun, 7:00 PM MST37Good2.840.7
Sun, 8:00 PM MST34Good5.237.9
Sun, 9:00 PM MST32Good7.934.2
Sun, 10:00 PM MST41Good930.1
Sun, 11:00 PM MST51Moderate11.126
Mon, 12:00 AM MST50Good8.822.3
Mon, 1:00 AM MST44Good6.819
Mon, 2:00 AM MST34Good4.416
Mon, 3:00 AM MST24Good2.713.7
Mon, 4:00 AM MST25Good4.612.7
Mon, 5:00 AM MST27Good5.511.9
Mon, 6:00 AM MST31Good6.311
Mon, 7:00 AM MST32Good5.99.8
Mon, 8:00 AM MST30Good5.19.5
Mon, 9:00 AM MST28Good4.89.9
Mon, 10:00 AM MST24Good3.811.1
Mon, 11:00 AM MST18Good213
Mon, 12:00 PM MST15Good2.116.1
Mon, 1:00 PM MST18Good3.120
Mon, 2:00 PM MST22Good324.1
Mon, 3:00 PM MST26Good2.628.6
Mon, 4:00 PM MST30Good2.132.4
Mon, 5:00 PM MST32Good2.635.2
Mon, 6:00 PM MST34Good2.537.1
Mon, 7:00 PM MST34Good2.837.2
Mon, 8:00 PM MST32Good3.535.7
Mon, 9:00 PM MST31Good6.233.6
Mon, 10:00 PM MST30Good6.230.9
Mon, 11:00 PM MST32Good6.227.8
Tue, 12:00 AM MST31Good5.424.3
Tue, 1:00 AM MST27Good4.420.5
Tue, 2:00 AM MST24Good416.7
Tue, 3:00 AM MST20Good2.914
Tue, 4:00 AM MST16Good2.212
Tue, 5:00 AM MST17Good3.210.2
Tue, 6:00 AM MST16Good2.89
Tue, 7:00 AM MST22Good58
Tue, 8:00 AM MST23Good4.38.4
Tue, 9:00 AM MST21Good3.610.1
Tue, 10:00 AM MST17Good2.212.5
Tue, 11:00 AM MST14Good1.715.3
Tue, 12:00 PM MST17Good2.118.9
Tue, 1:00 PM MST21Good2.823.2
Tue, 2:00 PM MST25Good2.627.5
Tue, 3:00 PM MST29Good2.731.9
Tue, 4:00 PM MST32Good2.335.3
Tue, 5:00 PM MST34Good3.137.6
Tue, 6:00 PM MST36Good2.839.5
Tue, 7:00 PM MST37Good2.440.1
Tue, 8:00 PM MST36Good1.939.5
Tue, 9:00 PM MST35Good3.639
Tue, 10:00 PM MST34Good7.637.9
Tue, 11:00 PM MST35Good7.337.6
Wed, 12:00 AM MST36Good6.637.2
Wed, 1:00 AM MST33Good4.636.3
Wed, 2:00 AM MST31Good4.834.7
Wed, 3:00 AM MST31Good4.233.4
Wed, 4:00 AM MST30Good3.632.4
Wed, 5:00 AM MST28Good4.530.9

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 Tempe Junction in satellite imagery today.

NOAA’s model forecasts near-surface smoke peaking at 0.1 µg/m³ around Sun, 7:00 AM MST.

Smoke on the radar over Tempe Junction

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 Tempe JunctionWarnings in Maricopa CountyLive radar over Tempe JunctionArizona 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.