September weather forecast
Garryowen, MT

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Weather in September

The first month of the autumn, September, is still a warm month in Garryowen, Montana, with temperature in the range of an average high of 75.2°F (24°C) and an average low of 54.7°F (12.6°C).

Temperature

The arrival of September signals a shift in temperature, down from a moderately hot 85.1°F (29.5°C) in August to a still warm 75.2°F (24°C). Garryowen's average low-temperature is measured at a fresh 54.7°F (12.6°C) during September.

Humidity

The average relative humidity in September in Garryowen is 42%.

Rainfall

In September, in Garryowen, the rain falls for 6.7 days. Throughout September, 1.06" (27mm) of precipitation is accumulated. Throughout the year, there are 103 rainfall days, and 11.97" (304mm) of precipitation is accumulated.

Snowfall

January through May, September through December are months with snowfall in Garryowen. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow. Throughout the year, there are 56.7 snowfall days, and 25.16" (639mm) of snow is accumulated.

Daylight

In September, the average length of the day is 12h and 31min.
On the first day of the month, sunrise is at 6:32 am and sunset at 7:46 pm. On the last day of September, in Garryowen, sunrise is at 7:07 am and sunset at 6:51 pm MDT.

Sunshine

In Garryowen, the average sunshine in September is 10.6h.

UV index

In September, the average daily maximum UV index in Garryowen is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for average individuals.
Note: In September, a regular UV index of 5 translates into these guidelines:
Ensure safety - Imperative it is to shield skin and eyes from damage. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.
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Frequently asked questions

What is the temperature in September in Garryowen?

In September, the average high-temperature and low-temperature are 75.2°F (24°C) and 54.7°F (12.6°C) respectively. The average heat index (a.k.a. 'real feel', 'apparent temperature'), which factors the actual air temperature with the relative humidity, in July is computed to be 87.8°F (31°C).

What is the average humidity in September in Garryowen?

In Garryowen, the average relative humidity in September is 42%.

How much does it rain in Garryowen in September?

In Garryowen, Montana, in September, it is raining for 6.7 days, with typically 1.06" (27mm) of accumulated precipitation.

When does it start to snow in Garryowen?

September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow.

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

In September, the average day length in Garryowen is 12h and 31min.

When is the sunrise / sunset in September in Garryowen?

On the first day of September in Garryowen, Montana, sunrise is at 6:32 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:51 pm MDT.

How long on average sun shines in September in Garryowen?

In Garryowen, the average sunshine duration in September is 10.6h.

What is the UV index reading in September in Garryowen?

In Garryowen, Montana, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate vulnerability from unsafe exposure to Sun's UV rays.
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
Garryowen, MT

Average temperature in September - Garryowen, MT
  • Average high temperature in September: 75.2°F

The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is December (31.3°F).

  • Average low temperature in September: 54.7°F

The month with the highest average low temperature is July (62.8°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).

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Average pressure in September
Garryowen, MT

Average pressure in September - Garryowen, MT
  • Average pressure in September: 29.93"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

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Average wind speed in September
Garryowen, MT

Average wind speed in September - Garryowen, MT
  • Average wind speed in September: 8mph

The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).

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Average humidity in September
Garryowen, MT

Average humidity in September - Garryowen, MT
  • Average humidity in September: 42%

The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (38%).

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Average rainfall in September
Garryowen, MT

Average rainfall in September - Garryowen, MT
  • Average rainfall in September: 1.06"

The wettest month (with the highest rainfall) is May (1.81").
The driest month (with the least rainfall) is August (0.63").

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Average rainfall days in September
Garryowen, MT

Average rainfall days in September - Garryowen, MT
  • Average rainfall days in September: 6.7 days

The month with the highest number of rainy days is May (13.6 days).
The month with the least rainy days is December (5.9 days).

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Average snowfall in September
Garryowen, MT

Average snowfall in September - Garryowen, MT
  • Average snowfall in September: 0.08"

The month with the highest snowfall is February (5.43").
The months with the least snowfall are June, July and August (0").

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Average snowfall days in September
Garryowen, MT

Average snowfall days in September - Garryowen, MT
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is February (12.5 days).
The 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
Garryowen, MT

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

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in September: 10h and 4min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 36min).

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Average sunshine days in September
Garryowen, MT

Average sunshine days in September - Garryowen, MT
  • Average sunshine days in September: 21.5 days

The month with the most sunshine days is September (21.5 days).
The month with the least sunshine days is February (13.3 days).

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Average UV index in September
Garryowen, MT

Average UV index in September - Garryowen, MT
  • Average UV index in September: 5

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

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Average cloud cover in September
Garryowen, MT

Average cloud cover in September - Garryowen, MT
  • Average cloud cover in September: 19

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

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Average visibility in September
Garryowen, MT

Average visibility in September - Garryowen, MT
  • 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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Garryowen, Montana, USA

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