September weather forecast
Saint Marie, MT

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Weather in September

The first month of the autumn, September, is also an agreeable month in Saint Marie, Montana, with an average temperature varying between 53.8°F (12.1°C) and 70.2°F (21.2°C).

Temperature

September is characterized by a reduction in the average high-temperature, from a moderately hot 81.7°F (27.6°C) in August to an agreeable 70.2°F (21.2°C). During the nights in September, the temperature in Saint Marie averages to a fresh 53.8°F (12.1°C).

Humidity

The average relative humidity in September is 47%.

Rainfall

In September, the rain falls for 9.1 days. Throughout September, 1.1" (28mm) of precipitation is accumulated. In Saint Marie, during the entire year, the rain falls for 90.8 days and collects up to 11.1" (282mm) of precipitation.

Snowfall

In Saint Marie, snow does not fall in June through September.

Daylight

The average length of the day in September is 12h and 34min.
On the first day of the month, sunrise is at 6:24 am and sunset at 7:46 pm. On the last day of September, in Saint Marie, sunrise is at 7:05 am and sunset at 6:46 pm MDT.

Sunshine

In September, the average sunshine is 10.1h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for average individuals.
Note: During September, 4 as the daily maximum UV index converts into the following advice:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Updated: Aug 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

The high-temperature, in September, in Saint Marie, is 70.2°F (21.2°C), while the low-temperature averages to 53.8°F (12.1°C). In August, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines air temperature and relative humidity, is computed to be 80.6°F (27°C).

What is the average humidity in September?

In September, the average relative humidity is 47%.

How many days does it rain in September?

In Saint Marie, during September, the rain falls for 9.1 days and regularly aggregates up to 1.1" (28mm) of precipitation.

When it does not snow?

June through September are months without snowfall.

Does it snow in Saint Marie in September?

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

How many hours of daylight does Saint Marie have in September?

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

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:24 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:46 pm MDT.

How many hours of sunshine does Saint Marie have in September?

In September, the average sunshine duration is 10.1h.

What is the UV index reading in September?

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Saint Marie, MT

Average temperature in September - Saint Marie, MT
  • Average high temperature in September: 70.2°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is February (23.7°F).

  • Average low temperature in September: 53.8°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is February (10.2°F).

Average pressure in September
Saint Marie, MT

Average pressure in September - Saint Marie, MT
  • Average pressure in September: 29.92"Hg

The month with the highest atmospheric pressure is February (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).

Average wind speed in September
Saint Marie, MT

Average wind speed in September - Saint Marie, MT
  • Average wind speed in September: 10.4mph

The windiest month (with the highest average wind speed) is April (11.7mph).
The calmest month (with the lowest average wind speed) is February (8.8mph).

Average humidity in September
Saint Marie, MT

Average humidity in September - Saint Marie, MT
  • Average humidity in September: 47%

The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is August (42%).

Average rainfall in September
Saint Marie, MT

Average rainfall in September - Saint Marie, MT
  • Average rainfall in September: 1.1"

The wettest month (with the highest rainfall) is June (2.01").
The driest months (with the least rainfall) are January and February (0.35").

Average rainfall days in September
Saint Marie, MT

Average rainfall days in September - Saint Marie, MT
  • Average rainfall days in September: 9.1 days

The month with the highest number of rainy days is May (13.8 days).
The month with the least rainy days is February (2.3 days).

Average snowfall in September
Saint Marie, MT

Average snowfall in September - Saint Marie, MT
  • Average snowfall in September: 0"

The month with the highest snowfall is December (2.6").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Saint Marie, MT

Average snowfall days in September - Saint Marie, MT
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is February (9.2 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Saint Marie, MT

Average daylight in September / Average sunshine in September - Saint Marie, 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: 10h and 1min

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

Average sunshine days in September
Saint Marie, MT

Average sunshine days in September - Saint Marie, MT
  • Average sunshine days in September: 18.9 days

The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is June (13.8 days).

Average UV index in September
Saint Marie, MT

Average UV index in September - Saint Marie, MT
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Saint Marie, MT

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

The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 16).

Average visibility in September
Saint Marie, MT

Average visibility in September - Saint Marie, 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).

Saint Marie, Montana, USA

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