September weather forecast
Willow Creek, MT

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Weather in September

The first month of the autumn, September, is still a pleasant month in Willow Creek, Montana, with temperature in the range of an average low of 44.4°F (6.9°C) and an average high of 70.9°F (21.6°C).

Temperature

Willow Creek's weather changes with the onset of September, slightly falling from a warm 81.9°F (27.7°C) in August to a pleasant 70.9°F (21.6°C). A noteworthy thermal contrast characterizes Willow Creek's September nights, with temperatures averaging at a chilly 44.4°F (6.9°C).

Humidity

The average relative humidity in September is 49%.

Rainfall

In Willow Creek, in September, it is raining for 8.4 days, with typically 0.91" (23mm) of accumulated precipitation. Throughout the year, there are 134.2 rainfall days, and 11.34" (288mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.5 snowfall days, it receives 0.83" (21mm) of snow. Throughout the year, there are 79.6 snowfall days, and 30.08" (764mm) of snow is accumulated.

Daylight

In Willow Creek, the average length of the day in September is 12h and 31min.
On the first day of the month, sunrise is at 6:48 am and sunset at 8:04 pm. On the last day of September, sunrise is at 7:24 am and sunset at 7:07 pm MDT.

Sunshine

In September, the average sunshine is 10h.

UV index

In Willow Creek, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.
Note: A maximum daily UV index of 3 during September morphs into the following directions:
Undertake protective steps - Recommendations to avoid sunburn are issued. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Stay sun-safe with clothing that is both closely woven and worn loosely. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Updated: Jul 11, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Willow Creek in September?

In September, in Willow Creek, the average high-temperature is 70.9°F (21.6°C), and the average low-temperature is 44.4°F (6.9°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines air temperature and relative humidity, in August is estimated at 82.4°F (28°C).

What is the average humidity in September?

In September, the average relative humidity is 49%.

How many days does it rain in September?

In Willow Creek, during September, the rain falls for 8.4 days and regularly aggregates up to 0.91" (23mm) of precipitation.

When does it start to snow?

September is the first month it typically snows. Throughout September, in the average 0.5 snowfall days, it receives 0.83" (21mm) of snow.

How many hours of daylight does Willow Creek have in September?

The average day length in September is 12h and 31min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:48 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:07 pm MDT.

How many hours of sunshine does Willow Creek have in September?

In Willow Creek, the average sunshine duration in September is 10h.

What is the UV index intensity in September?

In September, the average daily maximum UV index is 3. A UV Index of 3 to 5 symbolizes a medium health risk from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Willow Creek, MT

Average temperature in September - Willow Creek, MT
  • Average high temperature in September: 70.9°F

The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is December (28°F).

  • Average low temperature in September: 44.4°F

The month with the highest average low temperature is August (50.5°F).
The coldest month (with the lowest average low temperature) is December (12.7°F).

Average pressure in September
Willow Creek, MT

Average pressure in September - Willow Creek, MT
  • Average pressure in September: 29.98"Hg

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

Average wind speed in September
Willow Creek, MT

Average wind speed in September - Willow Creek, MT
  • Average wind speed in September: 4.6mph

The windiest month (with the highest average wind speed) is April (5.5mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).

Average humidity in September
Willow Creek, MT

Average humidity in September - Willow Creek, MT
  • Average humidity in September: 49%

The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is August (44%).

Average rainfall in September
Willow Creek, MT

Average rainfall in September - Willow Creek, MT
  • Average rainfall in September: 0.91"

The wettest month (with the highest rainfall) is June (1.57").
The driest month (with the least rainfall) is August (0.51").

Average rainfall days in September
Willow Creek, MT

Average rainfall days in September - Willow Creek, MT
  • Average rainfall days in September: 8.4 days

The month with the highest number of rainy days is April (16.5 days).
The month with the least rainy days is August (7.6 days).

Average snowfall in September
Willow Creek, MT

Average snowfall in September - Willow Creek, MT
  • Average snowfall in September: 0.83"

The month with the highest snowfall is February (6.02").
The months with the least snowfall are July and August (0").

Average snowfall days in September
Willow Creek, MT

Average snowfall days in September - Willow Creek, MT
  • Average snowfall days in September: 0.5 days

The month with the highest number of snowfall days is February (16.5 days).
The months with the least snowfall days are July and August (0 days).

Average daylight in September /
Average sunshine in September
Willow Creek, MT

Average daylight in September / Average sunshine in September - Willow Creek, MT
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).

  • Average sunshine in September: 10h and 0min

The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 5h and 54min).

Average sunshine days in September
Willow Creek, MT

Average sunshine days in September - Willow Creek, MT
  • Average sunshine days in September: 18.7 days

The month with the most sunshine days is September (18.7 days).
The month with the least sunshine days is April (9.3 days).

Average UV index in September
Willow Creek, MT

Average UV index in September - Willow Creek, MT
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Willow Creek, MT

Average cloud cover in September - Willow Creek, MT
  • Average cloud cover in September: 20

The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is August (Cloud cover 13).

Average visibility in September
Willow Creek, MT

Average visibility in September - Willow Creek, MT
  • Average visibility in September: 6mi

The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).

Willow Creek, Montana, USA

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