September weather forecast
Ulm, MT

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Weather in September

September, the first month of the autumn in Ulm, is still a pleasant month, with an average temperature varying between 70.5°F (21.4°C) and 49.5°F (9.7°C).

Temperature

Welcoming September, Ulm observes a shift in the average high-temperature, falling from August's moderately hot 81.1°F (27.3°C) to an agreeable 70.5°F (21.4°C). Nighttime temperatures consistently average a frosty 49.5°F (9.7°C) during September.

Humidity

The average relative humidity in September in Ulm, Montana, is 47%.

Rainfall

In Ulm, Montana, in September, during 8.7 rainfall days, 1.14" (29mm) of precipitation is typically accumulated. Throughout the year, in Ulm, there are 112.8 rainfall days, and 12.95" (329mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, September through December. September is the first month it typically snows in Ulm. Throughout September, in the average 0.7 snowfall days, it receives 2.05" (52mm) of snow. Throughout the year, there are 69.4 snowfall days, and 35.35" (898mm) of snow is accumulated.

Daylight

The average length of the day in September in Ulm is 12h and 32min.
On the first day of the month, sunrise is at 6:46 am and sunset at 8:05 pm. On the last day of September, sunrise is at 7:24 am and sunset at 7:06 pm MDT.

Sunshine

The average sunshine in September in Ulm is 9.6h.

UV index

In Ulm, Montana, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, the maximum UV index of 4 transforms into these recommendations:
Be vigilant - A duty to shield skin and eyes from injury exists. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures in Ulm?

Ulm in September has an average high-temperature of 70.5°F (21.4°C) and an average low-temperature of 49.5°F (9.7°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines relative humidity and air temperature, in August is estimated at 80.6°F (27°C).

What is the average humidity in September in Ulm?

In Ulm, the average relative humidity in September is 47%.

How much does it rain in Ulm in September?

In Ulm, during September, the rain falls for 8.7 days and regularly aggregates up to 1.14" (29mm) of precipitation.

When does it start to snow in Ulm?

September is the first month it typically snows. Throughout September, in the average 0.7 snowfall days, it receives 2.05" (52mm) of snow.

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

In Ulm, the average day length in September is 12h and 32min.

What time are sunrise and sunset in September in Ulm?

In September, on the first day of the month, sunrise is at 6:46 am and sunset at 8:05 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:06 pm MDT.

How long on average sun shines in September in Ulm?

In Ulm, the average sunshine duration in September is 9.6h.

How high is the UV index in September in Ulm?

In September, the average daily maximum UV index in Ulm is 4. A UV Index reading of 3 to 5 represents a moderate vulnerability from unprotected exposure to UV radiation.
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
Ulm, MT

Average temperature in September - Ulm, MT
  • Average high temperature in September: 70.5°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is December (29.5°F).

  • Average low temperature in September: 49.5°F

The month with the highest average low temperature is August (56.7°F).
The coldest month (with the lowest average low temperature) is December (17.4°F).

Average pressure in September
Ulm, MT

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

The months with the highest atmospheric pressure are January and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

Average wind speed in September
Ulm, MT

Average wind speed in September - Ulm, MT
  • Average wind speed in September: 8.2mph

The windiest months (with the highest average wind speed) are January and November (10.7mph).
The calmest month (with the lowest average wind speed) is August (7.3mph).

Average humidity in September
Ulm, MT

Average humidity in September - Ulm, MT
  • Average humidity in September: 47%

The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (41%).

Average rainfall in September
Ulm, MT

Average rainfall in September - Ulm, MT
  • Average rainfall in September: 1.14"

The wettest month (with the highest rainfall) is June (2.05").
The driest months (with the least rainfall) are January and July (0.63").

Average rainfall days in September
Ulm, MT

Average rainfall days in September - Ulm, MT
  • Average rainfall days in September: 8.7 days

The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is January (4.8 days).

Average snowfall in September
Ulm, MT

Average snowfall in September - Ulm, MT
  • Average snowfall in September: 2.05"

The month with the highest snowfall is February (6.34").
The months with the least snowfall are June, July and August (0").

Average snowfall days in September
Ulm, MT

Average snowfall days in September - Ulm, MT
  • Average snowfall days in September: 0.7 days

The month with the highest number of snowfall days is February (14.4 days).
The months with the least snowfall days are July and August (0 days).

Average daylight in September /
Average sunshine in September
Ulm, MT

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

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).

  • Average sunshine in September: 9h and 4min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).

Average sunshine days in September
Ulm, MT

Average sunshine days in September - Ulm, 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 (10.3 days).

Average UV index in September
Ulm, MT

Average UV index in September - Ulm, 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, October, November and December (UV index 2).

Average cloud cover in September
Ulm, MT

Average cloud cover in September - Ulm, MT
  • Average cloud cover in September: 24

The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 14).

Average visibility in September
Ulm, MT

Average visibility in September - Ulm, 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).

Ulm, Montana, USA

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