September weather forecast
Saint Ignatius, MT

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Weather in September

September, the first month of the autumn in Saint Ignatius, is also an agreeable month, with an average temperature fluctuating between 42.3°F (5.7°C) and 68.5°F (20.3°C).

Temperature

The onset of September is marked by a decrease in temperature, transitioning from a warm 79.3°F (26.3°C) in August to an agreeable 68.5°F (20.3°C). Saint Ignatius undergoes a major shift from daytime highs, averaging a wintry 42.3°F (5.7°C) during the night in September.

Humidity

In Saint Ignatius, Montana, the average relative humidity in September is 58%.

Rainfall

In Saint Ignatius, Montana, in September, during 9.3 rainfall days, 0.91" (23mm) of precipitation is typically accumulated. In Saint Ignatius, during the entire year, the rain falls for 129.9 days and collects up to 13.5" (343mm) of precipitation.

Snowfall

Months with snowfall in Saint Ignatius 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 0.47" (12mm) of snow. Throughout the year, there are 67.1 snowfall days, and 28.27" (718mm) of snow is accumulated.

Daylight

In Saint Ignatius, the average length of the day in September is 12h and 32min.
On the first day of September in Saint Ignatius, Montana, sunrise is at 6:56 am and sunset at 8:15 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 7:17 pm MDT.

Sunshine

In Saint Ignatius, the average sunshine in September is 9.3h.

UV index

The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: In September, the average maximum UV index of 3 translates into the following recommendations:
Undertake protective steps - Preventing sun damage is advised. To guard against the harmful effects of the Sun, minimize exposure during midday. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
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Frequently asked questions

What is the temperature in September in Saint Ignatius?

The high-temperature, in September, in Saint Ignatius, records 68.5°F (20.3°C), while the low-temperature is 42.3°F (5.7°C).

What is the average humidity in September in Saint Ignatius?

In Saint Ignatius, the average relative humidity in September is 58%.

How much does it rain in Saint Ignatius in September?

In Saint Ignatius, Montana, during September, the rain falls for 9.3 days and regularly aggregates up to 0.91" (23mm) of precipitation.

When does it start snowing in Saint Ignatius?

September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.47" (12mm) of snow.

What is the average length of the day in September in Saint Ignatius?

In September, the average day length in Saint Ignatius, Montana, is 12h and 32min.

When is the sunrise / sunset in September in Saint Ignatius?

On the first day of September in Saint Ignatius, sunrise is at 6:56 am and sunset at 8:15 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 7:17 pm MDT.

How long on average sun shines in September in Saint Ignatius?

In Saint Ignatius, the average sunshine duration in September is 9.3h.

What is the UV index reading in September in Saint Ignatius?

In Saint Ignatius, Montana, the average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to the Sun's 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
Saint Ignatius, MT

Average temperature in September - Saint Ignatius, MT
  • Average high temperature in September: 68.5°F

The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is December (28.4°F).

  • Average low temperature in September: 42.3°F

The month with the highest average low temperature is August (49.5°F).
The coldest month (with the lowest average low temperature) is December (16.7°F).

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Average pressure in September
Saint Ignatius, MT

Average pressure in September - Saint Ignatius, MT
  • Average pressure in September: 29.98"Hg

The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in September
Saint Ignatius, MT

Average wind speed in September - Saint Ignatius, MT
  • Average wind speed in September: 4mph

The windiest month (with the highest average wind speed) is April (4.8mph).
The calmest months (with the lowest average wind speed) are January, August and December (3.9mph).

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Average humidity in September
Saint Ignatius, MT

Average humidity in September - Saint Ignatius, MT
  • Average humidity in September: 58%

The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is August (49%).

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Average rainfall in September
Saint Ignatius, MT

Average rainfall in September - Saint Ignatius, MT
  • Average rainfall in September: 0.91"

The wettest month (with the highest rainfall) is June (2.2").
The driest months (with the least rainfall) are July and August (0.63").

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Average rainfall days in September
Saint Ignatius, MT

Average rainfall days in September - Saint Ignatius, MT
  • Average rainfall days in September: 9.3 days

The month with the highest number of rainy days is June (15.7 days).
The month with the least rainy days is August (7.4 days).

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Average snowfall in September
Saint Ignatius, MT

Average snowfall in September - Saint Ignatius, MT
  • Average snowfall in September: 0.47"

The month with the highest snowfall is February (6.5").
The months with the least snowfall are June, July and August (0").

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Average snowfall days in September
Saint Ignatius, MT

Average snowfall days in September - Saint Ignatius, MT
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is December (14.5 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
Saint Ignatius, MT

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

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).

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Average sunshine days in September
Saint Ignatius, MT

Average sunshine days in September - Saint Ignatius, MT
  • Average sunshine days in September: 18.2 days

The month with the most sunshine days is July (20.8 days).
The month with the least sunshine days is February (11 days).

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Average UV index in September
Saint Ignatius, MT

Average UV index in September - Saint Ignatius, MT
  • Average UV index in September: 3

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

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Average cloud cover in September
Saint Ignatius, MT

Average cloud cover in September - Saint Ignatius, MT
  • Average cloud cover in September: 23

The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 14).

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Average visibility in September
Saint Ignatius, MT

Average visibility in September - Saint Ignatius, MT
  • Average visibility in September: 6mi

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

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Saint Ignatius, Montana, USA

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