September weather forecast
Ravalli, MT

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Weather in September

September, the first month of the autumn in Ravalli, is still a pleasant month, with an average temperature varying between 68.5°F (20.3°C) and 42.3°F (5.7°C).

Temperature

As September commences, the average high-temperature shows a reduction, transitioning from a warm 79.3°F (26.3°C) in August to an agreeable 68.5°F (20.3°C). Ravalli logs a notable disparity from the daily highs during September, as the nighttime temperature lowers to an average of 42.3°F (5.7°C).

Humidity

In September, the average relative humidity in Ravalli, Montana, is 58%.

Rainfall

In Ravalli, during September, the rain falls for 9.3 days and regularly aggregates up to 0.91" (23mm) of precipitation. In Ravalli, during the entire year, the rain falls for 129.9 days and collects up to 13.5" (343mm) of precipitation.

Snowfall

January through May, September through December are months with snowfall in Ravalli. September is the first month it typically snows in Ravalli. Throughout September, in the average 0.2 snowfall days, it receives 0.47" (12mm) of snow. Throughout the year, in Ravalli, there are 67.1 snowfall days, and 28.27" (718mm) of snow is accumulated.

Daylight

The average length of the day in September is 12h and 32min.
On the first day of September in Ravalli, sunrise is at 6:56 am and sunset at 8:15 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 7:17 pm MDT.

Sunshine

In Ravalli, the average sunshine in September is 9.3h.

UV index

In September, the average daily maximum UV index in Ravalli is 3. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum high daily UV index of 3 during September translates into the following directions:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September in Ravalli?

Ravalli in September has an average high-temperature of 68.5°F (20.3°C) and an average low-temperature of 42.3°F (5.7°C).

What is the average humidity in September in Ravalli?

In September, the average relative humidity in Ravalli, Montana, is 58%.

How much does it rain in Ravalli in September?

In Ravalli, in September, it is raining for 9.3 days, with typically 0.91" (23mm) of accumulated precipitation.

When does it start to snow in Ravalli?

September is the first month it typically snows in Ravalli, Montana. Throughout September, in the average 0.2 snowfall days, it receives 0.47" (12mm) of snow.

How many hours of daylight does Ravalli have in September?

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

What time are sunrise and sunset in September in Ravalli?

In September, on the first day of the month, sunrise is at 6:56 am and sunset at 8:15 pm. On the last day of the month, in Ravalli, Montana, sunrise is at 7:35 am and sunset at 7:17 pm MDT.

How long on average sun shines in September in Ravalli?

In September, the average sunshine duration in Ravalli, Montana, is 9.3h.

What is the UV index reading in September in Ravalli?

In Ravalli, the average daily maximum UV index in September is 3. A UV Index reading 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
Ravalli, MT

Average temperature in September - Ravalli, MT
  • Average high temperature in September: 68.5°F

The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is December (28.4°F).

  • Average low temperature in September: 42.3°F

The month with the highest average low temperature is August (49.5°F).
The coldest month (with the lowest average low temperature) is December (16.7°F).

Average pressure in September
Ravalli, MT

Average pressure in September - Ravalli, MT
  • Average pressure in September: 29.98"Hg

The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in September
Ravalli, MT

Average wind speed in September - Ravalli, MT
  • Average wind speed in September: 4mph

The windiest month (with the highest average wind speed) is April (4.8mph).
The calmest months (with the lowest average wind speed) are January, August and December (3.9mph).

Average humidity in September
Ravalli, MT

Average humidity in September - Ravalli, MT
  • Average humidity in September: 58%

The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is August (49%).

Average rainfall in September
Ravalli, MT

Average rainfall in September - Ravalli, MT
  • Average rainfall in September: 0.91"

The wettest month (with the highest rainfall) is June (2.2").
The driest months (with the least rainfall) are July and August (0.63").

Average rainfall days in September
Ravalli, MT

Average rainfall days in September - Ravalli, MT
  • Average rainfall days in September: 9.3 days

The month with the highest number of rainy days is June (15.7 days).
The month with the least rainy days is August (7.4 days).

Average snowfall in September
Ravalli, MT

Average snowfall in September - Ravalli, MT
  • Average snowfall in September: 0.47"

The month with the highest snowfall is February (6.5").
The months with the least snowfall are June, July and August (0").

Average snowfall days in September
Ravalli, MT

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

The month with the highest number of snowfall days is December (14.5 days).
The months with the least snowfall days are June, July and August (0 days).

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

Average daylight in September / Average sunshine in September - Ravalli, 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 36min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).

Average sunshine days in September
Ravalli, MT

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

The month with the most sunshine days is July (20.8 days).
The month with the least sunshine days is February (11 days).

Average UV index in September
Ravalli, MT

Average UV index in September - Ravalli, MT
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are February and December (UV index 1).

Average cloud cover in September
Ravalli, MT

Average cloud cover in September - Ravalli, MT
  • Average cloud cover in September: 23

The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 14).

Average visibility in September
Ravalli, MT

Average visibility in September - Ravalli, MT
  • Average visibility in September: 6mi

The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).

Ravalli, Montana, USA

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