September weather forecast and climate
Columbia Falls, MT

September, the first month of the autumn, in Columbia Falls, is also an enjoyable month, with average temperature ranging between max 65.5°F (18.6°C) and min 39.2°F (4°C).

Temperature

In September, the average high-temperature drops, from a warm 76.8°F (24.9°C) in August, to an enjoyable 65.5°F (18.6°C). In Columbia Falls, the average low-temperature is 39.2°F (4°C).

Humidity

The average relative humidity in Columbia Falls is 64%.

Rainfall

In Columbia Falls, in September, during 8.5 rainfall days, 0.71" (18mm) of precipitation is typically accumulated. Throughout the year, there are 126.4 rainfall days, and 11.22" (285mm) of precipitation is accumulated.

Snowfall

Months with snowfall in Columbia Falls are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 97 snowfall days, and 33.86" (860mm) of snow is accumulated.

Daylight

In September, the average length of the day in Columbia Falls is 12.6h.

Sunshine

The average sunshine in Columbia Falls is 9.4h.

UV index

In Columbia Falls, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from the exposure to the Sun's UV rays for the ordinary person.
Note: In September, the average maximum UV index of 3 translate into the following recommendations:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in September in Columbia Falls?

The average high-temperature, in September, is 65.5°F (18.6°C), while the average low-temperature is 39.2°F (4°C).

What is the average humidity in September in Columbia Falls?

In September, the average relative humidity is 64%.

How much does it rain in Columbia Falls in September?

In Columbia Falls, during September, the rain falls for 8.5 days and regularly aggregates up to 0.71" (18mm) of precipitation.

When does it start snowing in Columbia Falls?

September is the first month it typically snows in Columbia Falls. Throughout September, in the average 0.3 snowfall days, it receives 0.04" (1mm) of snow.

How many hours of daylight does Columbia Falls have in September?

In Columbia Falls, Montana, the average length of the day in September is 12.6h.

How long on average sun shines in September in Columbia Falls?

The average sunshine in September in Columbia Falls, Montana, is 9.4h.

How high is the UV index in September in Columbia Falls?

In September, the average daily maximum UV index in Columbia Falls, Montana, is 3. A UV Index estimate of 3 to 5 represents a medium hazard to health from unprotected exposure to the UV radiation.
Average temperature in September - Columbia Falls, MT
  • Average high temperature in September: 65.5°F

The warmest month (with the highest average high temperature) is July (77.9°F).
The month with the lowest average high temperature is December (25.7°F).

  • Average low temperature in September: 39.2°F

The month with the highest average low temperature is August (45.5°F).
The coldest month (with the lowest average low temperature) is February (13.5°F).

Average pressure in September - Columbia Falls, MT
  • Average pressure in September: 29.97"

The month with the highest atmospheric pressure is January (30.16").
The month with the lowest atmospheric pressure is June (29.91").

Average wind speed in September - Columbia Falls, MT
  • Average wind speed in September: 3.8mph

The windiest month (with the highest average wind speed) is April (4.6mph).
The calmest months (with the lowest average wind speed) are August and December (3.7mph).

Average humidity in September - Columbia Falls, MT
  • Average humidity in September: 64%

The month with the highest relative humidity is January (93%).
The month with the lowest relative humidity is August (55%).

Average rainfall in September - Columbia Falls, MT
  • Average rainfall in September: 0.71"

The wettest month (with the highest rainfall) is June (1.42").
The driest month (with the least rainfall) is August (0.43").

Average rainfall days in September - Columbia Falls, MT
  • Average rainfall days in September: 8.5 days

The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is August (6.3 days).

Average snowfall in September - Columbia Falls, MT
  • Average snowfall in September: 0.04"

The month with the highest snowfall is January (7.72").
Months with the least snowfall are June, July and August (0").

Average snowfall days in September - Columbia Falls, MT
  • Average snowfall days in September: 0.3 days

The month with the highest number of snowfall days is December (19.1 days).
Months with the least snowfall days are July and August (0 days).

Average daylight in September / Average sunshine in September - Columbia Falls, MT
  • Average daylight in September: 12.6h

The month with the longest days is June (Average daylight: 16h).
The month with the shortest days is December (Average daylight: 8.4h).

  • Average sunshine in September: 9.4h

The month with the most sunshine is July (Average sunshine: 11.9h).
The month with the least sunshine is January (Average sunshine: 3.5h).

Average sunshine days in September - Columbia Falls, MT
  • Average sunshine days in September: 19 days

The month with the most sunshine days is July (21.5 days).
The month with the least sunshine days is March (7.7 days).

Average UV index in September - Columbia Falls, MT
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 1).

Average cloud cover in September - Columbia Falls, MT
  • Average cloud cover in September: 24

The month with the most cloud cover is January (Cloud cover 65).
Months with the least cloud cover are July and August (Cloud cover 15).

Average visibility in September - Columbia Falls, MT
  • Average visibility in September: 6mi

Months with the highest visibility are May, June, July, August, September and October (6mi).
The month with the lowest visibility is January (3mi).