September weather forecast
Troy, MT

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Weather in September

The first month of the autumn, September, is still a comfortable month in Troy, Montana, with temperature in the range of an average low of 39.7°F (4.3°C) and an average high of 66°F (18.9°C).

Temperature

With the onset of September, Troy experiences a modest temperature adjustment, with the average high-temperature receding from a warm 77.5°F (25.3°C) in August to a comfortable 66°F (18.9°C). September nights are characterized by a notable drop from daytime highs, with an average low-temperature of 39.7°F (4.3°C).

Humidity

The average relative humidity in September is 63%.

Rainfall

In Troy, Montana, during September, the rain falls for 8.5 days and regularly aggregates up to 0.91" (23mm) of precipitation. In Troy, Montana, during the entire year, the rain falls for 138.8 days and collects up to 18.15" (461mm) of precipitation.

Snowfall

January through May, September through December are months with snowfall in Troy. September is the first month it typically snows. Throughout September, in the average 0.4 snowfall days, it receives 0.71" (18mm) of snow. In Troy, during the entire year, snow falls for 91.8 days and aggregates up to 49.33" (1253mm) of snow.

Daylight

In Troy, the average length of the day in September is 12h and 34min.
On the first day of the month, sunrise is at 7:02 am and sunset at 8:24 pm. On the last day of September, sunrise is at 7:42 am and sunset at 7:23 pm MDT.

Sunshine

In September, the average sunshine is 9h.

UV index

In September, the average daily maximum UV index in Troy is 3. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.
Note: In September, the maximum UV index of 3 translates into these guidelines:
Take precautions - Protection against skin and eye damage is obliged. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
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Frequently asked questions

What are September temperatures in Troy?

The average high-temperature and low-temperature during September are 66°F (18.9°C) and 39.7°F (4.3°C) respectively.

What is the average humidity in September in Troy?

In September, the average relative humidity in Troy, Montana, is 63%.

How much does it rain in Troy in September?

In September, in Troy, the rain falls for 8.5 days. Throughout September, 0.91" (23mm) of precipitation is accumulated.

When does it start snowing in Troy?

September is the first month it typically snows in Troy, Montana. Throughout September, in the average 0.4 snowfall days, it receives 0.71" (18mm) of snow.

How many hours of daylight does Troy have in September?

The average day length in September is 12h and 34min.

When are sunrise and sunset in September in Troy?

On the first day of September in Troy, Montana, sunrise is at 7:02 am and sunset at 8:24 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 7:23 pm MDT.

How long on average sun shines in September in Troy?

The average sunshine duration in September is 9h.

What is the UV index intensity in September in Troy?

In September, the average daily maximum UV index in Troy, Montana, is 3. A UV Index reading of 3 to 5 represents a medium health risk 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
Troy, MT

Average temperature in September - Troy, MT
  • Average high temperature in September: 66°F

The warmest month (with the highest average high temperature) is August (77.5°F).
The month with the lowest average high temperature is December (27.1°F).

  • Average low temperature in September: 39.7°F

The month with the highest average low temperature is August (47.3°F).
The coldest month (with the lowest average low temperature) is December (15.1°F).

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Average pressure in September
Troy, MT

Average pressure in September - Troy, 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
Troy, MT

Average wind speed in September - Troy, MT
  • Average wind speed in September: 3.9mph

The windiest months (with the highest average wind speed) are April and June (4.5mph).
The calmest month (with the lowest average wind speed) is December (3.5mph).

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Average humidity in September
Troy, MT

Average humidity in September - Troy, MT
  • Average humidity in September: 63%

The month with the highest relative humidity is January (94%).
The month with the lowest relative humidity is August (53%).

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Average rainfall in September
Troy, MT

Average rainfall in September - Troy, MT
  • Average rainfall in September: 0.91"

The wettest month (with the highest rainfall) is December (2.24").
The driest month (with the least rainfall) is August (0.43").

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Average rainfall days in September
Troy, MT

Average rainfall days in September - Troy, MT
  • Average rainfall days in September: 8.5 days

The month with the highest number of rainy days is April (17.5 days).
The month with the least rainy days is August (5.9 days).

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Average snowfall in September
Troy, MT

Average snowfall in September - Troy, MT
  • Average snowfall in September: 0.71"

The month with the highest snowfall is January (11.34").
The months with the least snowfall are June, July and August (0").

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Average snowfall days in September
Troy, MT

Average snowfall days in September - Troy, MT
  • Average snowfall days in September: 0.4 days

The month with the highest number of snowfall days is December (20 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
Troy, MT

Average daylight in September / Average sunshine in September - Troy, MT
  • Average daylight in September: 12h and 4min

The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).

  • Average sunshine in September: 9h and 0min

The months with the most sunshine are July and August (Average sunshine: 11h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

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Average sunshine days in September
Troy, MT

Average sunshine days in September - Troy, MT
  • Average sunshine days in September: 19.5 days

The month with the most sunshine days is August (22.8 days).
The month with the least sunshine days is February (7.4 days).

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Average UV index in September
Troy, MT

Average UV index in September - Troy, MT
  • Average UV index in September: 3

The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).

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Average cloud cover in September
Troy, MT

Average cloud cover in September - Troy, MT
  • Average cloud cover in September: 26

The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 15).

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Average visibility in September
Troy, MT

Average visibility in September - Troy, MT
  • Average visibility in September: 6mi

The months with the highest visibility are May, June, July, August and September (6mi).
The month with the lowest visibility is January (2mi).

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Troy, Montana, USA

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