September weather forecast and climate
Billings, MT

The forest of trees in the plains, on the sandstone bluffs in Billings, Montana
The forest of trees in the plains, on the sandstone bluffs in Billings, Montana
September, the first month of the autumn, in Billings, is also an agreeable month, with average temperature ranging between min 52.5°F (11.4°C) and max 73.2°F (22.9°C).

Temperature

In September, the average high-temperature drops, from a moderately hot 83.1°F (28.4°C) in August, to a pleasant 73.2°F (22.9°C). The average low-temperature, is 52.5°F (11.4°C).

Humidity

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

Rainfall

In Billings, it is raining for 9.1 days, with typically 0.98" (25mm) of accumulated precipitation. Throughout the year, in Billings, there are 128.5 rainfall days, and 14.69" (373mm) of precipitation is accumulated.

Snowfall

January through May, September through December are months with snowfall in Billings, Montana. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.12" (3mm) of snow. In Billings, Montana, during the entire year, snow falls for 64.5 days, and aggregates up to 31.18" (792mm) of snow.

Daylight

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

Sunshine

In September, the average sunshine in Billings is 10.3h.

UV index

In Billings, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from the exposure to the Sun's UV radiation for average individuals.
Note: The daily maximum UV index of 4 interpret into the following advice:
Take precautions - Protection against the skin and eye damage is obliged. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. 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 Billings?

In Billings, Montana, in September, the average high-temperature is 73.2°F (22.9°C), and the average low-temperature is 52.5°F (11.4°C).

What is the average humidity in September in Billings?

The average relative humidity in September in Billings, Montana, is 44%.

How much does it rain in Billings in September?

In September, the rain falls for 9.1 days. Throughout September, 0.98" (25mm) of precipitation is accumulated.

When does it start to snow in Billings?

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

How many hours of daylight does Billings have in September?

The average length of the day in September in Billings is 12.5h.

How many hours of sunshine does Billings have in September?

In Billings, the average sunshine in September is 10.3h.

What is the UV index reading in September in Billings?

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat from the exposure to the Sun's UV rays.
Average temperature in September - Billings, MT
  • Average high temperature in September: 22.9°C

The warmest month (with the highest average high temperature) is July (29.6°C).
The month with the lowest average high temperature is December (-0.5°C).

  • Average low temperature in September: 11.4°C

The month with the highest average low temperature is July (15.8°C).
The coldest month (with the lowest average low temperature) is February (-7.6°C).

Average pressure in September - Billings, MT
  • Average pressure in September: 1014mbar

The month with the highest atmospheric pressure is January (1020.5mbar).
The month with the lowest atmospheric pressure is June (1011.3mbar).

Average wind speed in September - Billings, MT
  • Average wind speed in September: 12.9km/h

The windiest month (with the highest average wind speed) is January (15.9km/h).
The calmest month (with the lowest average wind speed) is July (11.5km/h).

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

The month with the highest relative humidity is January (76%).
The month with the lowest relative humidity is August (40%).

Average rainfall in September - Billings, MT
  • Average rainfall in September: 25mm

The wettest month (with the highest rainfall) is May (54mm).
The driest month (with the least rainfall) is July (18mm).

Average rainfall days in September - Billings, MT
  • Average rainfall days in September: 9.1 days

The month with the highest number of rainy days is May (17.6 days).
The month with the least rainy days is January (6.3 days).

Average snowfall in September - Billings, MT
  • Average snowfall in September: 3mm

The month with the highest snowfall is February (165mm).
Months with the least snowfall are June, July and August (0mm).

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

The month with the highest number of snowfall days is February (13.3 days).
Months with the least snowfall days are June, July and August (0 days).

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

The month with the longest days is June (Average daylight: 15.7h).
The month with the shortest days is December (Average daylight: 8.7h).

  • Average sunshine in September: 10.3h

The month with the most sunshine is July (Average sunshine: 11.8h).
The month with the least sunshine is February (Average sunshine: 5.2h).

Average sunshine days in September - Billings, MT
  • Average sunshine days in September: 18.8 days

The month with the most sunshine days is September (18.8 days).
The month with the least sunshine days is April (9.9 days).

Average UV index in September - Billings, 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 - Billings, MT
  • Average cloud cover in September: 21

The month with the most cloud cover is February (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 15).

Average visibility in September - Billings, MT
  • Average visibility in September: 10km

Months with the highest visibility are May, June, July, August, September and October (10km).
Months with the lowest visibility are January, February, March, April, November and December (9km).