September weather forecastMarion, MT
September
Weather in September
September, the first month of the autumn in Marion, is still a comfortable month, with temperature in the range of an average high of 67.1°F (19.5°C) and an average low of 41.5°F (5.3°C).Temperature
Marion in September undergoes a mild reduction in the average high-temperature, shifting from August's moderately hot 78.4°F (25.8°C) to an enjoyable 67.1°F (19.5°C). Marion reports a marked divergence from daytime peaks throughout September, with lows averaging at a wintry 41.5°F (5.3°C).Humidity
In Marion, the average relative humidity in September is 61%.Rainfall
In Marion, in September, it is raining for 10.2 days, with typically 0.98" (25mm) of accumulated precipitation. Throughout the year, there are 129.8 rainfall days, and 16.42" (417mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.4 snowfall days, it receives 0.2" (5mm) of snow. Throughout the year, there are 117.4 snowfall days, and 58.62" (1489mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 34min.On the first day of the month, sunrise is at 6:57 am and sunset at 8:19 pm. On the last day of September, sunrise is at 7:37 am and sunset at 7:19 pm MDT.
Sunshine
The average sunshine in September in Marion is 9.2h.UV index
In September, the average daily maximum UV index in Marion is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, the maximum UV index of 3 translates into these guidelines:
Prioritize safety - Recommendations to avert sunburn are shared. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Marion, MT
- Average high temperature in September: 67.1°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is December (27.1°F).
- Average low temperature in September: 41.5°F
The month with the highest average low temperature is July (48.4°F).
The coldest months (with the lowest average low temperature) are January and December (16.2°F).
Average pressure in September
Marion, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Marion, MT
- Average wind speed in September: 3.7mph
The windiest month (with the highest average wind speed) is April (4.7mph).
The calmest months (with the lowest average wind speed) are August and December (3.6mph).
Average humidity in September
Marion, MT
- Average humidity in September: 61%
The month with the highest relative humidity is January (93%).
The months with the lowest relative humidity are July and August (52%).
Average rainfall in September
Marion, MT
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is July (0.59").
Average rainfall days in September
Marion, MT
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is April (15.9 days).
The month with the least rainy days is December (6.5 days).
Average snowfall in September
Marion, MT
- Average snowfall in September: 0.2"
The month with the highest snowfall is December (12.36").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Marion, MT
- Average snowfall days in September: 0.4 days
The month with the highest number of snowfall days is January (22.3 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Marion, MT
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in September: 9h and 12min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Marion, MT
- Average sunshine days in September: 18.6 days
The month with the most sunshine days is July (20.8 days).
The month with the least sunshine days is February (7.1 days).
Average UV index in September
Marion, 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 January, February, November and December (UV index 1).
Average cloud cover in September
Marion, MT
- Average cloud cover in September: 25
The month with the most cloud cover is January (Cloud cover 64).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in September
Marion, MT
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The month with the lowest visibility is January (3mi).
