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 September's onset, the weather shows a temperature decrease, transitioning from a warm 81.5°F (27.5°C) in August to an agreeable 71.1°F (21.7°C). Harrison's average low-temperature for the month of September denotes a significant decline from the daily high, recording at a chilly 46°F (7.8°C).Humidity
In September, the average relative humidity is 57%.Rainfall
In Harrison, during September, the rain falls for 8.6 days and regularly aggregates up to 0.87" (22mm) of precipitation. Throughout the year, in Harrison, there are 148.8 rainfall days, and 23.86" (606mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.28" (7mm) of snow. In Harrison, during the entire year, snow falls for 67.9 days and aggregates up to 53.5" (1359mm) of snow.Daylight
The average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:07 am and sunset at 7:26 pm. On the last day of September, sunrise is at 6:45 am and sunset at 6:27 pm PDT.
Sunshine
In Harrison, the average sunshine in September is 9.7h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: A maximum UV index of 4 in September translates into the following recommendations:
Exercise prevention - Protecting skin and eyes from harm is required. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How much 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?
How high is the UV index in September?
Average temperature in September
Harrison, ID
- Average high temperature in September: 71.1°F
The warmest month (with the highest average high temperature) is August (81.5°F).
The month with the lowest average high temperature is December (32.2°F).
- Average low temperature in September: 46°F
The month with the highest average low temperature is August (52.9°F).
The coldest month (with the lowest average low temperature) is December (22.1°F).
Average pressure in September
Harrison, ID
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Harrison, ID
- Average wind speed in September: 4.3mph
The windiest month (with the highest average wind speed) is April (5.4mph).
The calmest months (with the lowest average wind speed) are August, September and December (4.3mph).
Average humidity in September
Harrison, ID
- Average humidity in September: 57%
The month with the highest relative humidity is January (92%).
The month with the lowest relative humidity is August (47%).
Average rainfall in September
Harrison, ID
- Average rainfall in September: 0.87"
The wettest month (with the highest rainfall) is January (3.39").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in September
Harrison, ID
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is March (18.6 days).
The month with the least rainy days is August (5.6 days).
Average snowfall in September
Harrison, ID
- Average snowfall in September: 0.28"
The month with the highest snowfall is January (15.2").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Harrison, ID
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (16.6 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Harrison, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 9h and 4min
The month with the most sunshine is August (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 3h and 24min).
Average sunshine days in September
Harrison, ID
- Average sunshine days in September: 19.5 days
The month with the most sunshine days is July (22.8 days).
The month with the least sunshine days is February (7.6 days).
Average UV index in September
Harrison, ID
- 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, February, November and December (UV index 1).
Average cloud cover in September
Harrison, ID
- Average cloud cover in September: 23
The months with the most cloud cover are January and December (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Harrison, ID
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).
Harrison, Idaho, USA
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