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
In Swan Valley, the average high-temperature in September drops from a moderately hot 76.5°F (24.7°C) in August to an enjoyable 66.6°F (19.2°C). Swan Valley records a consistent low-temperature average of 40.1°F (4.5°C) during September, indicating a significant difference from the daytime heat.Humidity
The average relative humidity in September is 53%.Rainfall
In Swan Valley, in September, during 11.1 rainfall days, 1.46" (37mm) of precipitation is typically accumulated. Throughout the year, in Swan Valley, there are 127 rainfall days, and 24.29" (617mm) of precipitation is accumulated.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.5 snowfall days, it receives 0.47" (12mm) of snow. In Swan Valley, during the entire year, snow falls for 126.6 days and aggregates up to 110.28" (2801mm) of snow.Daylight
In Swan Valley, the average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:50 am and sunset at 8:00 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 7:07 pm MDT.
Sunshine
In September, the average sunshine is 10.1h.UV index
In September, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: A maximum UV index of 3 in September translates into the following recommendations:
Exercise prevention - Protecting skin and eyes from harm is required. Direct Sun exposure should be minimized especially during midday when radiation is most intense. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How many days does it rain in September?
When does it start to snow in Swan Valley?
How many hours of daylight does Swan Valley have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Swan Valley have in September?
What is the UV index intensity in September?
Average temperature in September
Swan Valley, ID
- Average high temperature in September: 66.6°F
The warmest month (with the highest average high temperature) is July (77.5°F).
The month with the lowest average high temperature is December (24.3°F).
- Average low temperature in September: 40.1°F
The months with the highest average low temperature are July and August (45.3°F).
The coldest month (with the lowest average low temperature) is January (7.3°F).
Average pressure in September
Swan Valley, ID
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.28"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Swan Valley, ID
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is June (5.7mph).
The calmest month (with the lowest average wind speed) is January (4.3mph).
Average humidity in September
Swan Valley, ID
- Average humidity in September: 53%
The month with the highest relative humidity is February (94%).
The month with the lowest relative humidity is August (46%).
Average rainfall in September
Swan Valley, ID
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is February (2.91").
The driest month (with the least rainfall) is July (0.91").
Average rainfall days in September
Swan Valley, ID
- Average rainfall days in September: 11.1 days
The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is January (4.6 days).
Average snowfall in September
Swan Valley, ID
- Average snowfall in September: 0.47"
The month with the highest snowfall is February (22.91").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Swan Valley, ID
- Average snowfall days in September: 0.5 days
The months with the highest number of snowfall days are February and December (22.3 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Swan Valley, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 10h and 1min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 4h and 0min).
Average sunshine days in September
Swan Valley, ID
- Average sunshine days in September: 16.2 days
The month with the most sunshine days is September (16.2 days).
The month with the least sunshine days is April (5.3 days).
Average UV index in September
Swan Valley, ID
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 1).
Average cloud cover in September
Swan Valley, ID
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 67).
The months with the least cloud cover are July and August (Cloud cover 13).
Average visibility in September
Swan Valley, ID
- 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 and December (3mi).
Swan Valley, Idaho, USA
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