September weather forecast
Surprise, AZ

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Weather in September

September begins the slow transition from summer to fall. Temperatures start to drop, providing relief from the summer heat. A high of 95°F (35°C) indicates summer's slow departure. The sky fills with clouds more frequently, hinting at the approaching rainy season. Amid decreasing temperatures and cloudier skies, Surprise begins to welcome the feel of autumn.

Temperature

In Surprise, the beginning of September is marked by a marginally lowered average high-temperature, shifting from August's 100.9°F (38.3°C) to a still sweltering 95°F (35°C). Surprise, in September, observes a steady average low-temperature of 77°F (25°C).

Humidity

In Surprise, the average relative humidity in September is 30%.

Rainfall

In Surprise, during September, the rain falls for 7.1 days and regularly aggregates up to 1.18" (30mm) of precipitation. Throughout the year, there are 60.7 rainfall days, and 8.62" (219mm) of precipitation is accumulated.

Daylight

In September, the average length of the day is 12h and 22min.
On the first day of September in Surprise, sunrise is at 6:03 am and sunset at 6:54 pm. On the last day of the month, sunrise is at 6:23 am and sunset at 6:14 pm MST.

Sunshine

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

UV index

The average daily maximum UV index in September is 7. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: The daily high UV index of 7 in September translates into this advice:
Deflect overexposure. Sun protection is a necessity. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
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Frequently asked questions

How hot is it in Surprise in September?

In September, in Surprise, the average high-temperature is 95°F (35°C), and the average low-temperature is 77°F (25°C).

What is the average humidity in September in Surprise?

In Surprise, Arizona, the average relative humidity in September is 30%.

How many days does it rain in September in Surprise?

In Surprise, in September, it is raining for 7.1 days, with typically 1.18" (30mm) of accumulated precipitation.

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

In Surprise, the average day length in September is 12h and 22min.

When are sunrise and sunset in September in Surprise?

In September, on the first day of the month, sunrise is at 6:03 am and sunset at 6:54 pm. On the last day of the month, sunrise is at 6:23 am and sunset at 6:14 pm MST.

How many hours of sunshine does Surprise have in September?

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

How high is the UV index in September in Surprise?

In September, the average daily maximum UV index is 7. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Surprise, AZ

Average temperature in September - Surprise, AZ
  • Average high temperature in September: 95°F

The warmest month (with the highest average high temperature) is July (101.7°F).
The month with the lowest average high temperature is December (61.7°F).

  • Average low temperature in September: 77°F

The month with the highest average low temperature is August (83.1°F).
The coldest months (with the lowest average low temperature) are January and December (46°F).

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Average pressure in September
Surprise, AZ

Average pressure in September - Surprise, AZ
  • Average pressure in September: 29.86"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.8"Hg).

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Average wind speed in September
Surprise, AZ

Average wind speed in September - Surprise, AZ
  • Average wind speed in September: 5.3mph

The windiest month (with the highest average wind speed) is April (6.7mph).
The calmest month (with the lowest average wind speed) is December (4.7mph).

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Average humidity in September
Surprise, AZ

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

The month with the highest relative humidity is December (44%).
The month with the lowest relative humidity is June (17%).

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Average rainfall in September
Surprise, AZ

Average rainfall in September - Surprise, AZ
  • Average rainfall in September: 1.18"

The wettest month (with the highest rainfall) is July (1.3").
The driest month (with the least rainfall) is June (0.12").

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Average rainfall days in September
Surprise, AZ

Average rainfall days in September - Surprise, AZ
  • Average rainfall days in September: 7.1 days

The month with the highest number of rainy days is July (11.4 days).
The month with the least rainy days is June (1.2 days).

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Average daylight in September /
Average sunshine in September
Surprise, AZ

Average daylight in September / Average sunshine in September - Surprise, AZ
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 10h and 0min).

  • Average sunshine in September: 9h and 4min

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

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Average sunshine days in September
Surprise, AZ

Average sunshine days in September - Surprise, AZ
  • Average sunshine days in September: 20.3 days

The month with the most sunshine days is May (28.2 days).
The month with the least sunshine days is July (15.2 days).

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Average UV index in September
Surprise, AZ

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

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

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Average cloud cover in September
Surprise, AZ

Average cloud cover in September - Surprise, AZ
  • Average cloud cover in September: 10

The month with the most cloud cover is December (Cloud cover 20).
The month with the least cloud cover is June (Cloud cover 5).

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Average visibility in September
Surprise, AZ

Average visibility in September - Surprise, AZ
  • Average visibility in September: 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).

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Surprise, Arizona, USA

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