September weather forecast
Roberts, MT

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Weather in September

The first month of the autumn, September, is still a pleasant month in Roberts, Montana, with an average temperature fluctuating between 72°F (22.2°C) and 50.2°F (10.1°C).

Temperature

September brings a decrease in the average high-temperature, falling from August's moderately hot 81.1°F (27.3°C) to an agreeable 72°F (22.2°C). Roberts's nighttime temperature in September demonstrates a noticeable plunge to a cool 50.2°F (10.1°C).

Humidity

The average relative humidity in September is 45%.

Rainfall

In Roberts, Montana, during September, the rain falls for 6.9 days and regularly aggregates up to 0.79" (20mm) of precipitation. Throughout the year, there are 108.1 rainfall days, and 12.83" (326mm) of precipitation is accumulated.

Snowfall

January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.8 snowfall days, it receives 0.67" (17mm) of snow. Throughout the year, there are 61.5 snowfall days, and 41.77" (1061mm) of snow is accumulated.

Daylight

In September, the average length of the day is 12h and 31min.
On the first day of the month, sunrise is at 6:39 am and sunset at 7:53 pm. On the last day of September, sunrise is at 7:14 am and sunset at 6:58 pm MDT.

Sunshine

The average sunshine in September is 10.6h.

UV index

The average daily maximum UV index in September in Roberts is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum UV index of 4 during September translates into these guidelines:
Take precautions - Protection against sunburn is recommended. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures 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). In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is computed to be 80.6°F (27°C).

What is the average humidity in September in Roberts?

In Roberts, the average relative humidity in September is 45%.

How much does it rain in Roberts in September?

In Roberts, in September, it is raining for 6.9 days, with typically 0.79" (20mm) of accumulated precipitation.

When does it start to snow 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.

What is the average length of the day in September in Roberts?

The average day length in September in Roberts is 12h and 31min.

When is the sunrise / sunset in September in Roberts?

On the first day of September in Roberts, sunrise is at 6:39 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 6:58 pm MDT.

How long on average sun shines in September in Roberts?

In Roberts, Montana, the average sunshine duration in September is 10.6h.

How high is the UV index in September in Roberts?

In Roberts, Montana, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Roberts, MT

Average temperature in September - Roberts, MT
  • Average high temperature in September: 72°F

The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is December (30.7°F).

  • Average low temperature in September: 50.2°F

The months with the highest average low temperature are July and August (57.2°F).
The coldest month (with the lowest average low temperature) is February (16.7°F).

Average pressure in September
Roberts, MT

Average pressure in September - Roberts, MT
  • Average pressure in September: 29.96"Hg

The months with the highest atmospheric pressure are January and December (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).

Average wind speed in September
Roberts, MT

Average wind speed in September - Roberts, MT
  • Average wind speed in September: 6.9mph

The windiest month (with the highest average wind speed) is January (8.7mph).
The calmest month (with the lowest average wind speed) is August (6mph).

Average humidity in September
Roberts, MT

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 - Roberts, MT
  • Average rainfall in September: 0.79"

The wettest month (with the highest rainfall) is May (2.09").
The driest month (with the least rainfall) is January (0.51").

Average rainfall days in September
Roberts, MT

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 - Roberts, MT
  • Average snowfall in September: 0.67"

The month with the highest snowfall is February (6.81").
The months with the least snowfall are July and August (0").

Average snowfall days in September
Roberts, MT

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).
The 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 / Average sunshine in September - Roberts, MT
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in September: 10h and 4min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 12min).

Average sunshine days in September
Roberts, MT

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

The month with the highest UV index is July (UV index 6).
The 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 - Roberts, MT
  • Average cloud cover in September: 18

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

Average visibility in September
Roberts, MT

Average visibility in September - Roberts, 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).

Roberts, Montana, USA

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