August weather forecast
Phoenix, AZ

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The city of Phoenix, Arizona at dusk
The city of Phoenix, Arizona at dusk

Weather in August

August in Phoenix continues to be dominated by the summer heat, though slight hints of a reprieve become apparent. It segments in the last phase of the intense summer punctuated by occasional thunderstorms. Marginally lower than July, the average high temperature hangs around 102.6°F (39.2°C). The monsoon season brings with it increased rainfall and slightly higher cloud cover, tempering the persistent heat. Despite that, the city keeps up with its summer rhythm, ensuring continuous heat and minimal rain.

Temperature

Transitioning into August, Phoenix records an average high-temperature of a still sweltering 102.6°F (39.2°C), almost identical to July's 103.6°F (39.8°C). In Phoenix, the nighttime temperature averages to a warm 84.7°F (29.3°C) during August.

Humidity

The average relative humidity in August in Phoenix, Arizona, is 30%.

Rainfall

In Phoenix, in August, it is raining for 7.2 days, with typically 0.59" (15mm) of accumulated precipitation. In Phoenix, during the entire year, the rain falls for 44.6 days and collects up to 5.04" (128mm) of precipitation.

Snowfall

In Phoenix, snow does not fall in January through August, October through December.

Daylight

The average length of the day in August is 13h and 21min.
On the first day of the month, sunrise is at 5:41 am and sunset at 7:27 pm. On the last day of August, sunrise is at 6:02 am and sunset at 6:54 pm MST.

Sunshine

In Phoenix, the average sunshine in August is 12h.

UV index

The months with the highest UV index are May through August, with an average maximum UV index of 8. A UV Index value of 8 to 10 symbolizes a very high threat to health from unsafe exposure to UV radiation for the average person.
Note: The maximum UV index of 8 during August translates into these guidelines:
Always remain cautious. Unprotected skin and eyes are prone to swift harm. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Updated: Jul 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot is it in August?

During August, Phoenix experiences an average high-temperature of 102.6°F (39.2°C) and a low-temperature of 84.7°F (29.3°C).

What is the average humidity in August?

The average relative humidity in August is 30%.

How many days does it rain in August?

In Phoenix, in August, it is raining for 7.2 days, with typically 0.59" (15mm) of accumulated precipitation.

When it does not snow?

January through August, October through December are months without snowfall in Phoenix.

Does it snow in August?

In Phoenix, Arizona, in August, it doesn't snow. In September, it regularly snows.

What is the average length of the day in August in Phoenix?

In August, the average day length is 13h and 21min.

When is the sunrise / sunset in August?

On the first day of August, sunrise is at 5:41 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:02 am and sunset at 6:54 pm MST.

How many hours of sunshine does Phoenix have in August?

In Phoenix, the average sunshine duration in August is 12h.

What are the months with the highest UV index?

May through August, with an average maximum UV index of 8, are months with the highest UV index in Phoenix.

What is the UV index intensity in August?

The average daily maximum UV index in August is 8. A UV Index estimate of 8 to 10 represents a very high hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Phoenix, AZ

Average temperature in August - Phoenix, AZ
  • Average high temperature in August: 102.6°F

The warmest month (with the highest average high temperature) is July (103.6°F).
The month with the lowest average high temperature is December (63°F).

  • Average low temperature in August: 84.7°F

The month with the highest average low temperature is August (84.7°F).
The coldest month (with the lowest average low temperature) is January (47.5°F).

Average pressure in August
Phoenix, AZ

Average pressure in August - Phoenix, AZ
  • Average pressure in August: 29.87"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.81"Hg).

Average wind speed in August
Phoenix, AZ

Average wind speed in August - Phoenix, AZ
  • Average wind speed in August: 5.3mph

The windiest month (with the highest average wind speed) is April (6.4mph).
The calmest month (with the lowest average wind speed) is December (4.3mph).

Average humidity in August
Phoenix, AZ

Average humidity in August - Phoenix, AZ
  • Average humidity in August: 30%

The month with the highest relative humidity is December (43%).
The month with the lowest relative humidity is June (16%).

Average rainfall in August
Phoenix, AZ

Average rainfall in August - Phoenix, AZ
  • Average rainfall in August: 0.59"

The wettest month (with the highest rainfall) is July (0.75").
The driest months (with the least rainfall) are May and June (0.08").

Average rainfall days in August
Phoenix, AZ

Average rainfall days in August - Phoenix, AZ
  • Average rainfall days in August: 7.2 days

The month with the highest number of rainy days is July (7.8 days).
The month with the least rainy days is June (0.8 days).

Average snowfall in August
Phoenix, AZ

Average snowfall in August - Phoenix, AZ
  • Average snowfall in August: 0"

The month with the highest snowfall is September (0.04").
The months with the least snowfall are January, February, March, April, May, June, July, August, October, November and December (0").

Average snowfall days in August
Phoenix, AZ

Average snowfall days in August - Phoenix, AZ
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is September (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, October, November and December (0 days).

Average daylight in August /
Average sunshine in August
Phoenix, AZ

Average daylight in August / Average sunshine in August - Phoenix, AZ
  • Average daylight in August: 13h and 2min

The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).

  • Average sunshine in August: 12h and 0min

The month with the most sunshine is June (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).

Average sunshine days in August
Phoenix, AZ

Average sunshine days in August - Phoenix, AZ
  • Average sunshine days in August: 21.8 days

The month with the most sunshine days is May (29.2 days).
The month with the least sunshine days is July (21.1 days).

Average UV index in August
Phoenix, AZ

Average UV index in August - Phoenix, AZ
  • Average UV index in August: 8

The months with the highest UV index are May, June, July and August (UV index 8).
The month with the lowest UV index is December (UV index 3).

Average cloud cover in August
Phoenix, AZ

Average cloud cover in August - Phoenix, AZ
  • Average cloud cover in August: 12

The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is June (Cloud cover 5).

Average visibility in August
Phoenix, AZ

Average visibility in August - Phoenix, AZ
  • Average visibility in August: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Phoenix, Arizona, USA

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