Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The move into September indicates a reduction in the average high-temperature, down from August's moderately hot 78.8°F (26°C) to an enjoyable 67.3°F (19.6°C). Significant variation from daytime temperatures marks September, with the month recording a nightly average of 39.7°F (4.3°C).Humidity
The average relative humidity in September is 63%.Rainfall
In Thompson Falls, during September, the rain falls for 7.8 days and regularly aggregates up to 0.59" (15mm) of precipitation. In Thompson Falls, during the entire year, the rain falls for 152.1 days and collects up to 22.09" (561mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.31" (8mm) of snow. In Thompson Falls, Montana, during the entire year, snow falls for 90.2 days and aggregates up to 58.15" (1477mm) of snow.Daylight
The average length of the day in September is 12h and 33min.On the first day of September, sunrise is at 7:01 am and sunset at 8:21 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 7:21 pm MDT.
Sunshine
The average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: The daily high UV index of 3 during September translates into the following recommendations:
Ensure safety - Sun damage prevention is strongly urged. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How much does it rain in September?
When does it start to snow?
What is the average length of the day in September?
When are sunrise and sunset in September in Thompson Falls?
How many hours of sunshine does Thompson Falls have in September?
How high is the UV index in September?
Average temperature in September
Thompson Falls, MT
- Average high temperature in September: 67.3°F
The warmest months (with the highest average high temperature) are July and August (78.8°F).
The month with the lowest average high temperature is December (28.9°F).
- Average low temperature in September: 39.7°F
The month with the highest average low temperature is August (45.7°F).
The coldest month (with the lowest average low temperature) is December (16.2°F).
Average pressure in September
Thompson Falls, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Thompson Falls, MT
- Average wind speed in September: 4.2mph
The windiest month (with the highest average wind speed) is April (4.9mph).
The calmest month (with the lowest average wind speed) is December (4mph).
Average humidity in September
Thompson Falls, MT
- Average humidity in September: 63%
The month with the highest relative humidity is January (93%).
The months with the lowest relative humidity are July and August (53%).
Average rainfall in September
Thompson Falls, MT
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is January (3.11").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days in September
Thompson Falls, MT
- Average rainfall days in September: 7.8 days
The month with the highest number of rainy days is March (19.9 days).
The month with the least rainy days is August (5.9 days).
Average snowfall in September
Thompson Falls, MT
- Average snowfall in September: 0.31"
The month with the highest snowfall is February (15.12").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Thompson Falls, MT
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is December (20.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Thompson Falls, 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 0min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Thompson Falls, MT
- Average sunshine days in September: 20.3 days
The months with the most sunshine days are July and August (23.3 days).
The month with the least sunshine days is March (5.8 days).
Average UV index in September
Thompson Falls, 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
Thompson Falls, MT
- Average cloud cover in September: 25
The month with the most cloud cover is February (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in September
Thompson Falls, MT
- Average visibility in September: 6mi
The months with the highest visibility are June, July, August and September (6mi).
The months with the lowest visibility are January, February and December (3mi).
Thompson Falls, Montana, USA
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