September weather forecast
Mill Iron, MT

Share

Weather in September

September, the first month of the autumn in Mill Iron, is still a pleasant month, with an average temperature fluctuating between 72.1°F (22.3°C) and 54.1°F (12.3°C).

Temperature

The arrival of September signals a shift in temperature, down from a warm 81.9°F (27.7°C) in August to an agreeable 72.1°F (22.3°C). The temperature dips to an average of 54.1°F (12.3°C) during September nights.

Humidity

In Mill Iron, the average relative humidity in September is 48%.

Rainfall

In Mill Iron, in September, during 9.5 rainfall days, 1.5" (38mm) of precipitation is typically accumulated. In Mill Iron, during the entire year, the rain falls for 109 days and collects up to 15.12" (384mm) of precipitation.

Snowfall

January through May, September through December are months with snowfall. September is the first month it typically snows in Mill Iron. Throughout September, in the average 0.2 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, in Mill Iron, there are 62.4 snowfall days, and 21.97" (558mm) of snow is accumulated.

Daylight

In September, the average length of the day in Mill Iron is 12h and 31min.
On the first day of September in Mill Iron, sunrise is at 6:18 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:38 pm MDT.

Sunshine

In Mill Iron, the average sunshine in September is 10.2h.

UV index

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.
Note: The maximum UV index of 4 during September translates into these guidelines:
Exercise care. People with light skin might get burns in fewer than 30 minutes. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. 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. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
[Resources]

Frequently asked questions

What is the usual temperature for Mill Iron in September?

Mill Iron in September has an average high-temperature of 72.1°F (22.3°C) and an average low-temperature of 54.1°F (12.3°C). In August, the average heat index (a.k.a. 'real feel', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, is computed to be 82.4°F (28°C).

What is the average humidity in September in Mill Iron?

In Mill Iron, the average relative humidity in September is 48%.

How much does it rain in Mill Iron in September?

In Mill Iron, during September, the rain falls for 9.5 days and regularly aggregates up to 1.5" (38mm) of precipitation.

When does it start snowing in Mill Iron?

September is the first month it typically snows in Mill Iron. Throughout September, in the average 0.2 snowfall days, it receives 0.04" (1mm) of snow.

How many hours of daylight does Mill Iron have in September?

In Mill Iron, the average day length in September is 12h and 31min.

What time are sunrise and sunset in September in Mill Iron?

In September, on the first day of the month, sunrise is at 6:18 am and sunset at 7:34 pm. On the last day of the month, in Mill Iron, Montana, sunrise is at 6:54 am and sunset at 6:38 pm MDT.

How long on average sun shines in September in Mill Iron?

The average sunshine duration in September is 10.2h.

What is the UV index intensity in September in Mill Iron?

The average daily maximum UV index in September in Mill Iron, Montana, is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health 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
Mill Iron, MT

Average temperature in September - Mill Iron, MT
  • Average high temperature in September: 72.1°F

The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (26.1°F).

  • Average low temperature in September: 54.1°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).

[Resources]

Average pressure in September
Mill Iron, MT

Average pressure in September - Mill Iron, MT
  • Average pressure in September: 29.92"Hg

The months with the highest atmospheric pressure are January and February (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

[Resources]

Average wind speed in September
Mill Iron, MT

Average wind speed in September - Mill Iron, MT
  • Average wind speed in September: 10.9mph

The windiest months (with the highest average wind speed) are April and October (11.9mph).
The calmest months (with the lowest average wind speed) are July and August (10.1mph).

[Resources]

Average humidity in September
Mill Iron, MT

Average humidity in September - Mill Iron, MT
  • Average humidity in September: 48%

The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is August (46%).

[Resources]

Average rainfall in September
Mill Iron, MT

Average rainfall in September - Mill Iron, MT
  • Average rainfall in September: 1.5"

The wettest month (with the highest rainfall) is May (2.6").
The driest months (with the least rainfall) are January and December (0.55").

[Resources]

Average rainfall days in September
Mill Iron, MT

Average rainfall days in September - Mill Iron, MT
  • Average rainfall days in September: 9.5 days

The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is January (3.1 days).

[Resources]

Average snowfall in September
Mill Iron, MT

Average snowfall in September - Mill Iron, MT
  • Average snowfall in September: 0.04"

The month with the highest snowfall is February (3.86").
The months with the least snowfall are June, July and August (0").

[Resources]

Average snowfall days in September
Mill Iron, MT

Average snowfall days in September - Mill Iron, MT
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is February (12 days).
The months with the least snowfall days are July and August (0 days).

[Resources]

Average daylight in September /
Average sunshine in September
Mill Iron, MT

Average daylight in September / Average sunshine in September - Mill Iron, MT
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).

  • Average sunshine in September: 10h and 1min

The months with the most sunshine are July and August (Average sunshine: 11h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).

[Resources]

Average sunshine days in September
Mill Iron, MT

Average sunshine days in September - Mill Iron, MT
  • Average sunshine days in September: 17.8 days

The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is June (11.9 days).

[Resources]

Average UV index in September
Mill Iron, MT

Average UV index in September - Mill Iron, MT
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January and December (UV index 1).

[Resources]

Average cloud cover in September
Mill Iron, MT

Average cloud cover in September - Mill Iron, MT
  • Average cloud cover in September: 22

The month with the most cloud cover is February (Cloud cover 51).
The months with the least cloud cover are July and August (Cloud cover 18).

[Resources]

Average visibility in September
Mill Iron, MT

Average visibility in September - Mill Iron, 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).

[Resources]

Mill Iron, Montana, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location