September weather forecastSumatra, MT
September
Weather in September
September, the first month of the autumn in Sumatra, is also a moderately hot month, with an average temperature fluctuating between 54.9°F (12.7°C) and 74.5°F (23.6°C).Temperature
A shift in Sumatra's weather is observed as August turns into September, with the average high temperature reducing from 84.6°F (29.2°C) to a still warm 74.5°F (23.6°C). Sumatra's average low-temperature during September nights is observed to be a fresh 54.9°F (12.7°C).Humidity
In Sumatra, the average relative humidity in September is 43%.Rainfall
In Sumatra, in September, during 7.9 rainfall days, 1.26" (32mm) of precipitation is typically accumulated. Throughout the year, in Sumatra, there are 99.5 rainfall days, and 11.06" (281mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall in Sumatra. September is the first month it typically snows in Sumatra, Montana. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, in Sumatra, there are 47 snowfall days, and 15.83" (402mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 32min.On the first day of September in Sumatra, sunrise is at 6:31 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:51 pm MDT.
Sunshine
The average sunshine in September in Sumatra is 10.4h.UV index
In September, the average daily maximum UV index in Sumatra is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. 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. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sumatra, MT
- Average high temperature in September: 74.5°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The months with the lowest average high temperature are January and December (30.9°F).
- Average low temperature in September: 54.9°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in September
Sumatra, MT
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Sumatra, MT
- Average wind speed in September: 8.8mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is July (8.2mph).
Average humidity in September
Sumatra, MT
- Average humidity in September: 43%
The month with the highest relative humidity is January (79%).
The month with the lowest relative humidity is August (38%).
Average rainfall in September
Sumatra, MT
- Average rainfall in September: 1.26"
The wettest month (with the highest rainfall) is May (1.81").
The driest months (with the least rainfall) are January, November and December (0.47").
Average rainfall days in September
Sumatra, MT
- Average rainfall days in September: 7.9 days
The month with the highest number of rainy days is May (13.7 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in September
Sumatra, MT
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (3.74").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Sumatra, MT
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (10.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Sumatra, MT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 10h and 24min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The months with the least sunshine are February and December (Average sunshine: 5h and 18min).
Average sunshine days in September
Sumatra, MT
- Average sunshine days in September: 19.7 days
The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is April (14.2 days).
Average UV index in September
Sumatra, MT
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Sumatra, MT
- Average cloud cover in September: 20
The month with the most cloud cover is February (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in September
Sumatra, 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).
