Phoenix Forecast

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Air Quality Hourly Forecast | Phoenix

Click on each day to view forecast.

Monday Forecast:


Ozone

97 AQI
Max 8-hr Avg: 69 ppb

PM10

26 AQI
24-hr Avg: 28 µg/m3

PM2.5

25 AQI
24-hr Avg: 6.1 µg/m3

Tuesday Forecast:

Alert: Ozone High Pollution Advisory in effect for Tuesday

Ozone

119 AQI
Max 8-hr Avg: 76 ppb

PM10

31 AQI
24-hr Avg: 33 µg/m3

PM2.5

28 AQI
24-hr Avg: 6.6 µg/m3

Wednesday Forecast:

Alert: Ozone High Pollution Watch in effect for Wednesday

Ozone

101 AQI
Max 8-hr Avg: 71 ppb

PM10

33 AQI
24-hr Avg: 36 µg/m3

PM2.5

33 AQI
24-hr Avg: 8.0 µg/m3

Thursday Forecast:


Ozone

93 AQI
Max 8-hr Avg: 68 ppb

PM10

34 AQI
24-hr Avg: 37 µg/m3

PM2.5

32 AQI
24-hr Avg: 7.7 µg/m3

Friday Forecast:


Ozone

67 AQI
Max 8-hr Avg: 60 ppb

PM10

31 AQI
24-hr Avg: 33 µg/m3

PM2.5

29 AQI
24-hr Avg: 6.9 µg/m3

Air Quality By Pollutant:

Pollutant
Monday
7/26/2021
Tuesday
7/27/2021
Wednesday
7/28/2021
Thursday
7/29/2021
Friday
7/30/2021
O3
97
119
101
93
67
PM10
26
31
33
34
31
PM2.5
25
28
33
32
29
Pollutant
MON
TUE
WED
THU
FRI
O3
97
119
101
93
67
PM10
26
31
33
34
31
PM2.5
25
28
33
32
29
O3 = Ozone, PM10 = Particles ≤ 10 microns, PM2.5 = Particles ≤ 2.5 microns

Forecast Discussion:

What a weekend weather-wise! Since Thursday, July 22nd, Phoenix Sky Harbor officially picked up 1.30 inches; however, that was one of the lower measurements across the Valley. Looking at rainfall data over the past seven days from the network of rain gauges operated by the Maricopa County Flood Control District, nearly every gauge in the Valley measured over one inch of rain, with some seeing much more, including: (1) just east of New River: 5.24 inches (2) Old Town Scottsdale: 4.69 inches, (3) near Westgate: 3.31 inches (4) Chandler Heights: 3.15 inches.

The other big story were the cold temperatures for July! The high temperature in Phoenix on Friday and Saturday was 83 degrees, and on Sunday, it was 81. This three-day streak of temperatures below 85 broke the record for the longest number of consecutive days, with a high below 85 degrees in July! The old record was two days in 1955 and 1911.

Ok, enough about what happened this weekend, let's go to the forecast!

This morning, water vapor satellite shows the disturbance that brought all the rain to the region is now moving through the southern portion of California, with high pressure centered over Wyoming. With Arizona being on the back-side of the disturbance, not expecting much in the way of storm activity today, with afternoon high temperatures rising back into the mid to upper 90s.

Late tomorrow into the weekend, high pressure will expand and be elongated along an axis from Wyoming to Mississippi. This pattern will continue an east/southeast flow across Arizona, which will allow disturbances to move into the region and possibly enhance thunderstorm activity. Slight storm chances will return to the Valley as early as tomorrow afternoon/evening; however, a more well-defined disturbance will move into the region late Thursday into Friday, with storm chances once again increasing. These storms are not forecast to be as slow-moving or as widespread as this weekend, so not expecting as impressive rain totals, but storms will still be capable of producing very heavy rainfall. And with an already saturated ground, it will not take much for washes to start running and for flooding.

As for air quality, PM-10 (dust) and PM-2.5 (smoke) are not forecast to be an issue through the forecast period. Ozone, on the other hand, will be very tricky. Before the active weather period started last week, ozone values were quickly rising in Phoenix, even with added cloud cover. Also, yesterday, locations in Northern Arizona saw ozone in the Moderate AQI category. As a result, ozone is forecast to rise into the upper Moderate AQI category today before rising above the federal health standard Tuesday and Wednesday. Due to this, an Ozone High Pollution Advisory will be issued for Phoenix on Tuesday with an Ozone High Pollution Watch for Wednesday. With more active weather possible in the Valley by the end of the week, we are forecasting ozone to lower back into the Moderate AQI category.

Overall, the active Monsoon 2021 pattern continues!

- M. Pace
ADEQ Meteorologist


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