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
As August shifts into September, a slight alteration in temperatures is observed, with average highs reducing from a warm 82.2°F (27.9°C) to a pleasant 72°F (22.2°C). In September, the temperature drops to an average of 52°F (11.1°C) at night.Humidity
In September, the average relative humidity is 57%.Rainfall
In Napoleon, during September, the rain falls for 8.9 days and regularly aggregates up to 1.22" (31mm) of precipitation. Throughout the year, there are 105.9 rainfall days, and 15" (381mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 32min.On the first day of September in Napoleon, sunrise is at 7:00 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 7:37 am and sunset at 7:20 pm CDT.
Sunshine
The average sunshine in September is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Guard yourself - An obligation to protect skin and eyes from harm exists. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Napoleon in September?
What is the average humidity in September?
How many days does it rain in September in Napoleon?
When it does not snow?
Does it snow in September?
What is the average length of the day in September in Napoleon?
When are sunrise and sunset in September?
How many hours of sunshine does Napoleon have in September?
What is the UV index intensity in September?
Average temperature in September
Napoleon, ND
- Average high temperature in September: 72°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (20.8°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (6.1°F).
Average pressure in September
Napoleon, ND
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Napoleon, ND
- Average wind speed in September: 9.8mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).
Average humidity in September
Napoleon, ND
- Average humidity in September: 57%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (55%).
Average rainfall in September
Napoleon, ND
- Average rainfall in September: 1.22"
The wettest month (with the highest rainfall) is June (2.28").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in September
Napoleon, ND
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is February (3.4 days).
Average snowfall in September
Napoleon, ND
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.33").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Napoleon, ND
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (15.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Napoleon, ND
- Average daylight in September: 12h and 3min
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 42min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Napoleon, ND
- Average sunshine days in September: 19.9 days
The month with the most sunshine days is September (19.9 days).
The month with the least sunshine days is March (12.3 days).
Average UV index in September
Napoleon, ND
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Napoleon, ND
- Average cloud cover in September: 25
The month with the most cloud cover is February (Cloud cover 60).
The months with the least cloud cover are July and August (Cloud cover 21).
Average visibility in September
Napoleon, ND
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
Napoleon, North Dakota, USA
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