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
With the onset of September, Saint Mary's's average high-temperature slightly adjusts, moderately receding from August's moderate 59°F (15°C) to a cool 51.1°F (10.6°C). Saint Mary's in September experiences a low-temperature average of 40.1°F (4.5°C).Humidity
In September, the average relative humidity is 81%.Rainfall
In Saint Mary's, in September, it is raining for 14.5 days, with typically 1.77" (45mm) of accumulated precipitation. In Saint Mary's, during the entire year, the rain falls for 104.5 days and collects up to 15.75" (400mm) 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 0.8 snowfall days, it receives 0.12" (3mm) of snow. Throughout the year, there are 71.4 snowfall days, and 22.72" (577mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 53min.On the first day of September, sunrise is at 7:44 am and sunset at 9:59 pm. On the last day of the month, sunrise is at 8:59 am and sunset at 8:24 pm AKDT.
Sunshine
In Saint Mary's, the average sunshine in September is 4.5h.UV index
In Saint Mary's, the average daily maximum UV index in September is 2. A UV Index of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for average individuals.Note: A daily high UV index of 2 in September leads to these guidelines:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Saint Mary's in September?
What is the average humidity in September?
How many days does it rain in September?
When does it start snowing?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September in Saint Mary's?
How high is the UV index in September?
Average temperature in September
Saint Mary's, AK
- Average high temperature in September: 51.1°F
The warmest month (with the highest average high temperature) is July (61.5°F).
The month with the lowest average high temperature is January (11.3°F).
- Average low temperature in September: 40.1°F
The month with the highest average low temperature is July (47.5°F).
The coldest month (with the lowest average low temperature) is January (2.3°F).
Average pressure in September
Saint Mary's, AK
- Average pressure in September: 29.72"Hg
The month with the highest atmospheric pressure is July (29.91"Hg).
The months with the lowest atmospheric pressure are October and December (29.67"Hg).
Average wind speed in September
Saint Mary's, AK
- Average wind speed in September: 10.2mph
The windiest month (with the highest average wind speed) is February (11.9mph).
The calmest month (with the lowest average wind speed) is July (8.9mph).
Average humidity in September
Saint Mary's, AK
- Average humidity in September: 81%
The months with the highest relative humidity are January, February, March and December (91%).
The month with the lowest relative humidity is June (66%).
Average rainfall in September
Saint Mary's, AK
- Average rainfall in September: 1.77"
The wettest month (with the highest rainfall) is August (2.13").
The driest months (with the least rainfall) are January and June (0.87").
Average rainfall days in September
Saint Mary's, AK
- Average rainfall days in September: 14.5 days
The month with the highest number of rainy days is August (17.8 days).
The months with the least rainy days are January and February (2.4 days).
Average snowfall in September
Saint Mary's, AK
- Average snowfall in September: 0.12"
The month with the highest snowfall is February (5.28").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Saint Mary's, AK
- Average snowfall days in September: 0.8 days
The month with the highest number of snowfall days is February (11.4 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Saint Mary's, AK
- Average daylight in September: 12h and 5min
The month with the longest days is June (Average daylight: 19h and 36min).
The month with the shortest days is December (Average daylight: 5h and 18min).
- Average sunshine in September: 4h and 3min
The month with the most sunshine is May (Average sunshine: 7h and 54min).
The month with the least sunshine is December (Average sunshine: 2h and 36min).
Average sunshine days in September
Saint Mary's, AK
- Average sunshine days in September: 12.4 days
The month with the most sunshine days is March (19.5 days).
The month with the least sunshine days is August (10.9 days).
Average UV index in September
Saint Mary's, AK
- Average UV index in September: 2
The months with the highest UV index are May, June, July and August (UV index 3).
The months with the lowest UV index are March, November and December (UV index 1).
Average cloud cover in September
Saint Mary's, AK
- Average cloud cover in September: 64
The month with the most cloud cover is July (Cloud cover 68).
The month with the least cloud cover is June (Cloud cover 54).
Average visibility in September
Saint Mary's, AK
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April, November and December (5mi).
Saint Mary's, Alaska, USA
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