September weather forecast and climate
Otter, MT

September, the first month of the autumn, in Otter, is still a warm month, with average temperature fluctuating between 74.1°F (23.4°C) and 52.7°F (11.5°C).

Temperature

In September, the average high-temperature decreases, from 83.7°F (28.7°C) in August, to a still warm 74.1°F (23.4°C). In Otter, Montana, in September, the average low-temperature is 52.7°F (11.5°C).

Humidity

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

Rainfall

In September, in Otter, Montana, the rain falls for 8.6 days. Throughout September, 0.83" (21mm) of precipitation is accumulated. In Otter, during the entire year, the rain falls for 127.6 days and collects up to 14.25" (362mm) of precipitation.

Snowfall

January through May, September through December are months with snowfall. 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 Otter, Montana, during the entire year, snow falls for 65.3 days, and aggregates up to 28.82" (732mm) of snow.

Daylight

The average length of the day in Otter, Montana, is 12.5h.

Sunshine

In September, the average sunshine in Otter is 10.8h.

UV index

In Otter, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from the exposure to the Sun's UV radiation for the average person.
Note: The average daily UV index of 4 transform into the following instructions:
Take precautions. Light skin individuals may get burned in less than 30 minutes. 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 Otter?

In September, in Otter, the average high-temperature is 74.1°F (23.4°C), and the average low-temperature is 52.7°F (11.5°C).

What is the average humidity in September in Otter?

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

How much does it rain in Otter in September?

In September, the rain falls for 8.6 days. Throughout September, 0.83" (21mm) of precipitation is accumulated.

When does it start to snow in Otter?

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

How many hours of daylight does Otter have in September?

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

How many hours of sunshine does Otter have in September?

In Otter, Montana, the average sunshine in September is 10.8h.

How high is the UV index in September in Otter?

In September, the average daily maximum UV index in Otter, Montana, is 4. A UV Index reading of 3 to 5 represents a medium health risk from unsafe exposure to the Sun's UV rays.
Average temperature in September - Otter, MT
  • Average high temperature in September: 23.4°C

The warmest month (with the highest average high temperature) is July (29.7°C).
The month with the lowest average high temperature is December (-0.5°C).

  • Average low temperature in September: 11.5°C

The month with the highest average low temperature is July (16.4°C).
The coldest months (with the lowest average low temperature) are January and February (-8.8°C).

Average pressure in September - Otter, MT
  • Average pressure in September: 1013.5mbar

The month with the highest atmospheric pressure is January (1020.3mbar).
The month with the lowest atmospheric pressure is June (1010.7mbar).

Average wind speed in September - Otter, MT
  • Average wind speed in September: 12.2km/h

The windiest month (with the highest average wind speed) is April (14.6km/h).
The calmest month (with the lowest average wind speed) is December (10.9km/h).

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

Months with the highest relative humidity are January and February (79%).
The month with the lowest relative humidity is August (40%).

Average rainfall in September - Otter, MT
  • Average rainfall in September: 21mm

The wettest month (with the highest rainfall) is May (67mm).
The driest month (with the least rainfall) is December (17mm).

Average rainfall days in September - Otter, MT
  • Average rainfall days in September: 8.6 days

The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is January (6.3 days).

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

The month with the highest snowfall is February (132mm).
Months with the least snowfall are June, July and August (0mm).

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

The month with the highest number of snowfall days is February (14.3 days).
Months with the least snowfall days are June, July and August (0 days).

Average daylight in September / Average sunshine in September - Otter, 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: 10.8h

Months with the most sunshine are July and August (Average sunshine: 11.9h).
The month with the least sunshine is February (Average sunshine: 5.7h).

Average sunshine days in September - Otter, MT
  • Average sunshine days in September: 18.2 days

The month with the most sunshine days is September (18.2 days).
The month with the least sunshine days is May (9.6 days).

Average UV index in September - Otter, 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 - Otter, MT
  • Average cloud cover in September: 18

The month with the most cloud cover is February (Cloud cover 41).
Months with the least cloud cover are July and August (Cloud cover 14).

Average visibility in September - Otter, 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).