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
Irwin's weather changes with the onset of September, slightly falling from a warm 76.5°F (24.7°C) in August to a comfortable 66.6°F (19.2°C). A noticeable temperature swing characterizes Irwin's September nights, dipping to an average of 40.1°F (4.5°C).Humidity
The average relative humidity in September is 53%.Rainfall
In Irwin, in September, during 11.1 rainfall days, 1.46" (37mm) of precipitation is typically accumulated. In Irwin, during the entire year, the rain falls for 127 days and collects up to 24.29" (617mm) of precipitation.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows in Irwin. Throughout September, in the average 0.5 snowfall days, it receives 0.47" (12mm) of snow. Throughout the year, there are 126.6 snowfall days, and 110.28" (2801mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:50 am and sunset at 7:59 pm. On the last day of September, sunrise is at 7:22 am and sunset at 7:07 pm MDT.
Sunshine
In September, the average sunshine is 10.1h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the maximum UV index of 3 translates into these guidelines:
Undertake protective steps - Recommendations to avoid sunburn are issued. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Irwin 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?
How many hours of sunshine does Irwin have in September?
How high is the UV index in September?
Average temperature in September
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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
Irwin, 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).
Irwin, Idaho, USA
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