September weather forecast and climate
Birney, MT

The first month of the autumn, September, is also a moderately hot month in Birney, Montana, with temperature in the range of an average low of 52.7°F (11.5°C) and an average high of 74.1°F (23.4°C).

Temperature

In Birney, the average high-temperature decreases, from 83.7°F (28.7°C) in August, to a still warm 74.1°F (23.4°C). In Birney, Montana, the average low-temperature is 52.7°F (11.5°C).

Humidity

In September, the average relative humidity is 44%.

Rainfall

In Birney, in September, it is raining for 8.6 days, with typically 0.83" (21mm) of accumulated precipitation. In Birney, during the entire year, the rain falls for 127.6 days and collects up to 14.25" (362mm) of precipitation.

Snowfall

Months with snowfall in Birney 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 0.12" (3mm) of snow. Throughout the year, in Birney, there are 65.3 snowfall days, and 28.82" (732mm) of snow is accumulated.

Daylight

In Birney, the average length of the day is 12.5h.

Sunshine

The average sunshine in September is 10.8h.

UV index

In Birney, Montana, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to the UV radiation for the average person.
Note: The average daily UV index of 4 in September transform into the following instructions:
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. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the temperature in September in Birney?

In Birney, in September, the average high-temperature is 74.1°F (23.4°C), and the average low-temperature is 52.7°F (11.5°C).

What is the average humidity in September in Birney?

In Birney, the average relative humidity in September is 44%.

How much does it rain in Birney in September?

In Birney, in September, during 8.6 rainfall days, 0.83" (21mm) of precipitation is typically accumulated.

When does it start snowing in Birney?

September is the first month it typically snows in Birney. Throughout September, in the average 0.2 snowfall days, it receives 0.12" (3mm) of snow.

How many hours of daylight does Birney have in September?

In September, the average length of the day in Birney, Montana, is 12.5h.

How long on average sun shines in September in Birney?

In September, the average sunshine in Birney, Montana, is 10.8h.

What is the UV index intensity in September in Birney?

In September, the average daily maximum UV index in Birney is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat from unsafe exposure to the Sun's UV rays.
Average temperature in September - Birney, MT
  • Average high temperature in September: 74.1°F

The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is December (31.1°F).

  • Average low temperature in September: 52.7°F

The month with the highest average low temperature is July (61.5°F).
The coldest months (with the lowest average low temperature) are January and February (16.2°F).

Average pressure in September - Birney, MT
  • Average pressure in September: 29.93"

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

Average wind speed in September - Birney, MT
  • Average wind speed in September: 7.6mph

The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest months (with the lowest average wind speed) are July and December (6.8mph).

Average humidity in September - Birney, MT
  • Average humidity in September: 44%

Months with the highest relative humidity are January and February (79%).
The month with the lowest relative humidity is August (40%).

Average rainfall in September - Birney, MT
  • Average rainfall in September: 0.83"

The wettest month (with the highest rainfall) is May (2.64").
The driest month (with the least rainfall) is December (0.67").

Average rainfall days in September - Birney, MT
  • Average rainfall days in September: 8.6 days

The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is January (6.3 days).

Average snowfall in September - Birney, MT
  • Average snowfall in September: 0.12"

The month with the highest snowfall is February (5.2").
Months with the least snowfall are June, July and August (0").

Average snowfall days in September - Birney, MT
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is February (14.3 days).
Months with the least snowfall days are June, July and August (0 days).

Average daylight in September / Average sunshine in September - Birney, MT
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.6h).
The month with the shortest days is December (Average daylight: 8.8h).

  • Average sunshine in September: 10.8h

Months with the most sunshine are July and August (Average sunshine: 11.9h).
The month with the least sunshine is February (Average sunshine: 5.7h).

Average sunshine days in September - Birney, MT
  • Average sunshine days in September: 18.2 days

The month with the most sunshine days is September (18.2 days).
The month with the least sunshine days is May (9.6 days).

Average UV index in September - Birney, MT
  • Average UV index in September: 4

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

Average cloud cover in September - Birney, MT
  • Average cloud cover in September: 18

The month with the most cloud cover is February (Cloud cover 41).
Months with the least cloud cover are July and August (Cloud cover 14).

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

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).