September weather forecast and climate
Cheyenne, WY

A sunny day in front of the State Capitol building in Cheyenne, Wyoming
A sunny day in front of the State Capitol building in Cheyenne, Wyoming

Weather in September

The first month of the autumn, September, is also a moderately hot month in Cheyenne, Wyoming, with average temperature fluctuating between 73.8°F (23.2°C) and 52.3°F (11.3°C).

Temperature

In September, the average high-temperature slightly decreases, from a moderately hot 81.1°F (27.3°C) in August, to a still warm 73.8°F (23.2°C). The average low-temperature, in September, is 52.3°F (11.3°C).

Humidity

The average relative humidity in Cheyenne is 44%.

Rainfall

In September, in Cheyenne, the rain falls for 8.4 days. Throughout September, 0.87" (22mm) of precipitation is accumulated. In Cheyenne, Wyoming, during the entire year, the rain falls for 116 days and collects up to 14.57" (370mm) of precipitation.

Snowfall

In Cheyenne snow does not fall in June through September.

Daylight

The average length of the day in September is 12.4h.

Sunshine

In Cheyenne, the average sunshine in September is 10.7h.

UV index

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: In September, the average maximum UV index of 4 translate into the following recommendations:
Take precautions - Protection against sunburn is recommended. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. 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.
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FAQ

What is the temperature in September in Cheyenne?

In Cheyenne, in September, the average high-temperature is 73.8°F (23.2°C), and the average low-temperature is 52.3°F (11.3°C).

What is the average humidity in September in Cheyenne?

The average relative humidity in September in Cheyenne, Wyoming, is 44%.

How much does it rain in Cheyenne in September?

In September, in Cheyenne, the rain falls for 8.4 days. Throughout September, 0.87" (22mm) of precipitation is accumulated.

Does it snow in Cheyenne in September?

In Cheyenne, in September, it doesn't snow. In October, it regularly snows.

When it does not snow in Cheyenne?

June through September are months without snowfall in Cheyenne.

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

In Cheyenne, Wyoming, the average length of the day in September is 12.4h.

How many hours of sunshine does Cheyenne have in September?

The average sunshine in September in Cheyenne is 10.7h.

How high is the UV index in September in Cheyenne?

In Cheyenne, Wyoming, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health threat from unsafe exposure to the Sun's UV rays.

Average temperature in September
Cheyenne, WY

Average temperature in September - Cheyenne, WY
  • Average high temperature in September: 73.8°F

The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is December (34.7°F).

  • Average low temperature in September: 52.3°F

The month with the highest average low temperature is July (59.9°F).
The coldest month (with the lowest average low temperature) is December (20.3°F).

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Average pressure in September
Cheyenne, WY

Average pressure in September - Cheyenne, WY
  • Average pressure in September: 29.96"

The month with the highest atmospheric pressure is January (30.14").
The month with the lowest atmospheric pressure is June (29.87").

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Average wind speed in September
Cheyenne, WY

Average wind speed in September - Cheyenne, WY
  • Average wind speed in September: 9.6mph

The windiest month (with the highest average wind speed) is January (14.2mph).
The calmest month (with the lowest average wind speed) is August (8.7mph).

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Average humidity in September
Cheyenne, WY

Average humidity in September - Cheyenne, WY
  • Average humidity in September: 44%

The month with the highest relative humidity is February (64%).
The month with the lowest relative humidity is August (43%).

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Average rainfall in September
Cheyenne, WY

Average rainfall in September - Cheyenne, WY
  • Average rainfall in September: 0.87"

The wettest month (with the highest rainfall) is May (2.95").
The driest month (with the least rainfall) is January (0.43").

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Average rainfall days in September
Cheyenne, WY

Average rainfall days in September - Cheyenne, WY
  • Average rainfall days in September: 8.4 days

The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (4.7 days).

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Average snowfall in September
Cheyenne, WY

Average snowfall in September - Cheyenne, WY
  • Average snowfall in September: 0"

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

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Average snowfall days in September
Cheyenne, WY

Average snowfall days in September - Cheyenne, WY
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is February (11.3 days).
Months with the least snowfall days are June, July and August (0 days).

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Average daylight in September /
Average sunshine in September
Cheyenne, WY

Average daylight in September / Average sunshine in September - Cheyenne, WY
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 15.1h).
The month with the shortest days is December (Average daylight: 9.3h).

  • Average sunshine in September: 10.7h

Months with the most sunshine are July and August (Average sunshine: 11.6h).
The month with the least sunshine is February (Average sunshine: 6.5h).

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Average sunshine days in September
Cheyenne, WY

Average sunshine days in September - Cheyenne, WY
  • Average sunshine days in September: 19 days

The month with the most sunshine days is January (20.7 days).
The month with the least sunshine days is April (9.3 days).

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Average UV index in September
Cheyenne, WY

Average UV index in September - Cheyenne, WY
  • Average UV index in September: 4

Months with the highest UV index are July and August (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 2).

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Average cloud cover in September
Cheyenne, WY

Average cloud cover in September - Cheyenne, WY
  • Average cloud cover in September: 18

Months with the most cloud cover are April and May (Cloud cover 32).
The month with the least cloud cover is September (Cloud cover 18).

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Average visibility in September
Cheyenne, WY

Average visibility in September - Cheyenne, WY
  • Average visibility in September: 6mi

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

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