September weather forecast and climate
Roberts, MT

The first month of the autumn, September, is also an agreeable month in Roberts, Montana, with temperature in the range of an average high of 72°F (22.2°C) and an average low of 50.2°F (10.1°C).

Temperature

In Roberts, the average high-temperature in September drops, from a warm 81.1°F (27.3°C) in August, to an agreeable 72°F (22.2°C). In Roberts, the average low-temperature is 50.2°F (10.1°C).

Humidity

The average relative humidity in Roberts is 45%.

Rainfall

In Roberts, during September, the rain falls for 6.9 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Roberts, during the entire year, the rain falls for 108.1 days and collects up to 12.83" (326mm) of precipitation.

Snowfall

Months with snowfall in Roberts, Montana, are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.8 snowfall days, it receives 0.67" (17mm) of snow. In Roberts, during the entire year, snow falls for 61.5 days, and aggregates up to 41.77" (1061mm) of snow.

Daylight

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

Sunshine

In Roberts, the average sunshine is 10.6h.

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to the Sun's UV rays for average individuals.
Note: The average daily UV index of 4 transform into the following instructions:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. 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. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in September in Roberts?

In September, in Roberts, the average high-temperature is 72°F (22.2°C), and the average low-temperature is 50.2°F (10.1°C).

What is the average humidity in September in Roberts?

The average relative humidity in September in Roberts, Montana, is 45%.

How much does it rain in Roberts in September?

In Roberts, Montana, in September, during 6.9 rainfall days, 0.79" (20mm) of precipitation is typically accumulated.

When does it start snowing in Roberts?

September is the first month it typically snows in Roberts, Montana. Throughout September, in the average 0.8 snowfall days, it receives 0.67" (17mm) of snow.

How many hours of daylight does Roberts have in September?

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

How long on average sun shines in September in Roberts?

The average sunshine in September is 10.6h.

How high is the UV index in September in Roberts?

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from the exposure to the Sun's UV radiation.
Average temperature in September - Roberts, MT
  • Average high temperature in September: 22.2°C

The warmest month (with the highest average high temperature) is July (28.3°C).
The month with the lowest average high temperature is December (-0.7°C).

  • Average low temperature in September: 10.1°C

Months with the highest average low temperature are July and August (14°C).
The coldest month (with the lowest average low temperature) is February (-8.5°C).

Average pressure in September - Roberts, MT
  • Average pressure in September: 1014.6mbar

The month with the highest atmospheric pressure is January (1021.1mbar).
The month with the lowest atmospheric pressure is June (1011.9mbar).

Average wind speed in September - Roberts, MT
  • Average wind speed in September: 11.1km/h

The windiest month (with the highest average wind speed) is January (14km/h).
The calmest month (with the lowest average wind speed) is August (9.6km/h).

Average humidity in September - Roberts, MT
  • Average humidity in September: 45%

The month with the highest relative humidity is January (76%).
The month with the lowest relative humidity is August (41%).

Average rainfall in September - Roberts, MT
  • Average rainfall in September: 20mm

The wettest month (with the highest rainfall) is May (53mm).
The driest month (with the least rainfall) is January (13mm).

Average rainfall days in September - Roberts, MT
  • Average rainfall days in September: 6.9 days

The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (4 days).

Average snowfall in September - Roberts, MT
  • Average snowfall in September: 17mm

The month with the highest snowfall is February (173mm).
Months with the least snowfall are July and August (0mm).

Average snowfall days in September - Roberts, MT
  • Average snowfall days in September: 0.8 days

The month with the highest number of snowfall days is February (10.8 days).
Months with the least snowfall days are July and August (0 days).

Average daylight in September / Average sunshine in September - Roberts, 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: 10.6h

The month with the most sunshine is July (Average sunshine: 11.9h).
The month with the least sunshine is February (Average sunshine: 6.2h).

Average sunshine days in September - Roberts, MT
  • Average sunshine days in September: 18.4 days

The month with the most sunshine days is December (19.7 days).
The month with the least sunshine days is May (10.5 days).

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

The month with the highest UV index is July (UV index 6).
Months with the lowest UV index are January, February, March, November and December (UV index 2).

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

The month with the most cloud cover is February (Cloud cover 38).
Months with the least cloud cover are July and August (Cloud cover 15).

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

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