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 onset of September brings a small shift in high-temperatures, falling from a warm 84.2°F (29°C) in August to a still moderately hot 75.7°F (24.3°C). Nighttime temperatures in Alpena consistently average a fresh 54.5°F (12.5°C) during September.Humidity
With an average relative humidity of 62%, September is the least humid month.Rainfall
In September, the rain falls for 9.8 days. Throughout September, 1.38" (35mm) of precipitation is accumulated. In Alpena, during the entire year, the rain falls for 101.8 days and collects up to 18.19" (462mm) of precipitation.Snowfall
In Alpena, snow does not fall in May through September.Daylight
In Alpena, the average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:57 am and sunset at 8:09 pm. On the last day of September, sunrise is at 7:30 am and sunset at 7:15 pm CDT.
Sunshine
The average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum high UV index of 4 in September translates into the following recommendations:
Prioritize safety - Suggestions to prevent sun damage are offered. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Alpena?
What is the least humid month?
What is the average humidity in September in Alpena?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Alpena have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Alpena have in September?
What is the UV index reading in September?
Average temperature in September
Alpena, SD
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (23.2°F).
- Average low temperature in September: 54.5°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 (8.2°F).
Average pressure in September
Alpena, SD
- Average pressure in September: 29.96"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Alpena, SD
- Average wind speed in September: 9.7mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest months (with the lowest average wind speed) are July and August (8.6mph).
Average humidity in September
Alpena, SD
- Average humidity in September: 62%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is September (62%).
Average rainfall in September
Alpena, SD
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is June (2.8").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in September
Alpena, SD
- Average rainfall days in September: 9.8 days
The month with the highest number of rainy days is June (15.2 days).
The month with the least rainy days is February (1.8 days).
Average snowfall in September
Alpena, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.54").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Alpena, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Alpena, SD
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Alpena, SD
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is November (21.8 days).
The month with the least sunshine days is June (12.3 days).
Average UV index in September
Alpena, SD
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and November (UV index 1).
Average cloud cover in September
Alpena, SD
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 22).
Average visibility in September
Alpena, SD
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Alpena, South Dakota, USA
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