Phoenix
Arizona, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Phoenix, AZ

The city of Phoenix, Arizona, at dusk
The city of Phoenix, Arizona, at dusk
September, the first month of the autumn, in Phoenix, is still a torrid month, with temperature in the range of an average low of 78.8°F (26°C) and an average high of 96.3°F (35.7°C).

Temperature

In Phoenix, the average high-temperature slightly decreases, from a very hot 102.6°F (39.2°C) in August, to a still torrid 96.3°F (35.7°C). The average low-temperature, is 78.8°F (26°C).

Humidity

In Phoenix, the average relative humidity is 30%.

Rainfall

In September, the rain falls for 4.7 days. Throughout September, 0.67" (17mm) of precipitation is accumulated. Throughout the year, there are 44.6 rainfall days, and 5.04" (128mm) of precipitation is accumulated.

Snowfall

The only month with snowfall is September. September is the month with the most snowfall in Phoenix. Snow falls for 0.1 days and accumulates 0.04" (1mm) of snow.

Daylight

In Phoenix, the average length of the day is 12.4h.

Sunshine

In September, the average sunshine in Phoenix is 9.7h.

UV index

In September, the average daily maximum UV index in Phoenix is 7. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to the Sun's UV rays for the average person.
Note: The daily maximum UV index of 7 in September interpret into the following advice:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in September in Phoenix?

The average high-temperature, in September, is 96.3°F (35.7°C), while the average low-temperature is 78.8°F (26°C).

What is the average humidity in September in Phoenix?

The average relative humidity in September in Phoenix is 30%.

How many days does it rain in September in Phoenix?

In Phoenix, Arizona, in September, it is raining for 4.7 days, with typically 0.67" (17mm) of accumulated precipitation.

When does it start snowing in Phoenix?

September is the first month it typically snows in Phoenix. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow.

What is the snowiest month in Phoenix?

September is the month with the most snowfall in Phoenix. Snow falls for 0.1 days and accumulates 0.04" (1mm) of snow.

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

In Phoenix, Arizona, the average length of the day in September is 12.4h.

How long on average sun shines in September in Phoenix?

In Phoenix, Arizona, the average sunshine in September is 9.7h.

What is the UV index intensity in September in Phoenix?

In Phoenix, Arizona, the average daily maximum UV index in September is 7. A UV Index estimate of 6 to 7 represents a high health threat from the exposure to the Sun's UV rays.
Average temperature in September - Phoenix, AZ
  • Average high temperature in September: 35.7°C

The warmest month (with the highest average high temperature) is July (39.8°C).
The month with the lowest average high temperature is December (17.2°C).

  • Average low temperature in September: 26°C

The month with the highest average low temperature is August (29.3°C).
The coldest month (with the lowest average low temperature) is January (8.6°C).

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

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

Average rainfall in September - Phoenix, AZ
  • Average rainfall in September: 17mm

The wettest month (with the highest rainfall) is July (19mm).
Driest months (with the lowest rainfall) are May and June (2mm).

Average rainfall days in September - Phoenix, AZ
  • Average rainfall days in September: 4.7 days

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

Average snowfall in September - Phoenix, AZ
  • Average snowfall in September: 1mm

The month with the highest snowfall is September (1mm).
Months with the lowest snowfall are January, February, March, April, May, June, July, August, October, November and December (0mm).

Average snowfall days in September - Phoenix, AZ
  • Average snowfall days in September: 0.1 days

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

Average daylight in September / Average sunshine in September - Phoenix, AZ
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.3h).
The month with shortest days is December (Average daylight: 10h).

  • Average sunshine in September: 9.7h

The month with most sunshine is June (Average sunshine: 12.1h).
The month with least sunshine is December (Average sunshine: 6.8h).

Average UV index in September - Phoenix, AZ
  • Average UV index in September: 7

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).