September weather forecast
Sun Valley, NV

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Sun Valley, Nevada, with an average temperature fluctuating between 74.8°F (23.8°C) and 49.8°F (9.9°C).

Temperature

Sun Valley's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's warm 82.9°F (28.3°C) to a still moderately hot 74.8°F (23.8°C). The nighttime temperature during September exhibits a clear drop from daytime highs, settling at a chilly 49.8°F (9.9°C).

Humidity

In Sun Valley, the average relative humidity in September is 33%.

Rainfall

In September, in Sun Valley, the rain falls for 2.5 days. Throughout September, 0.16" (4mm) of precipitation is accumulated. Throughout the year, there are 68 rainfall days, and 8.07" (205mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.12" (3mm) of snow. In Sun Valley, during the entire year, snow falls for 33.2 days and aggregates up to 23.62" (600mm) of snow.

Daylight

In Sun Valley, Nevada, the average length of the day in September is 12h and 26min.
On the first day of the month, sunrise is at 6:28 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:42 pm PDT.

Sunshine

In September, the average sunshine is 11.1h.

UV index

In Sun Valley, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: In September, the maximum UV index of 4 suggests these recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Always opt for UVA and UVB-resistant sunglasses on radiant days. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Updated: Aug 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

The high-temperature during September is 74.8°F (23.8°C) and the low-temperature is 49.8°F (9.9°C).

What is the average humidity in September?

The average relative humidity in September is 33%.

How much does it rain in September?

In September, the rain falls for 2.5 days. Throughout September, 0.16" (4mm) of precipitation is accumulated.

When does it start snowing?

September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.12" (3mm) of snow.

What is the average length of the day in September?

The average day length in September is 12h and 26min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:28 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:42 pm PDT.

How long on average sun shines in September?

The average sunshine duration in September is 11.1h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
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 September
Sun Valley, NV

Average temperature in September - Sun Valley, NV
  • Average high temperature in September: 74.8°F

The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is December (37.8°F).

  • Average low temperature in September: 49.8°F

The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is December (23.4°F).

Average pressure in September
Sun Valley, NV

Average pressure in September - Sun Valley, NV
  • Average pressure in September: 29.94"Hg

The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in September
Sun Valley, NV

Average wind speed in September - Sun Valley, NV
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is April (7.3mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).

Average humidity in September
Sun Valley, NV

Average humidity in September - Sun Valley, NV
  • Average humidity in September: 33%

The month with the highest relative humidity is January (73%).
The months with the lowest relative humidity are July and August (28%).

Average rainfall in September
Sun Valley, NV

Average rainfall in September - Sun Valley, NV
  • Average rainfall in September: 0.16"

The wettest month (with the highest rainfall) is February (1.38").
The driest months (with the least rainfall) are July and August (0.08").

Average rainfall days in September
Sun Valley, NV

Average rainfall days in September - Sun Valley, NV
  • Average rainfall days in September: 2.5 days

The month with the highest number of rainy days is March (11.2 days).
The month with the least rainy days is August (1.8 days).

Average snowfall in September
Sun Valley, NV

Average snowfall in September - Sun Valley, NV
  • Average snowfall in September: 0.12"

The month with the highest snowfall is February (6.06").
The months with the least snowfall are June, July and August (0").

Average snowfall days in September
Sun Valley, NV

Average snowfall days in September - Sun Valley, NV
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is December (7.8 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Sun Valley, NV

Average daylight in September / Average sunshine in September - Sun Valley, NV
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in September: 11h and 1min

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

Average sunshine days in September
Sun Valley, NV

Average sunshine days in September - Sun Valley, NV
  • Average sunshine days in September: 26.9 days

The month with the most sunshine days is August (28.2 days).
The month with the least sunshine days is March (15.9 days).

Average UV index in September
Sun Valley, NV

Average UV index in September - Sun Valley, NV
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
Sun Valley, NV

Average cloud cover in September - Sun Valley, NV
  • Average cloud cover in September: 9

The month with the most cloud cover is December (Cloud cover 33).
The months with the least cloud cover are July and August (Cloud cover 7).

Average visibility in September
Sun Valley, NV

Average visibility in September - Sun Valley, NV
  • 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).

Sun Valley, Nevada, USA

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