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
September brings a decrease in the average high-temperature, falling from August's moderately hot 82.6°F (28.1°C) to a pleasant 72.7°F (22.6°C). In stark contrast to the day's heat, the temperature dips to an average of 47.3°F (8.5°C) during September nights.Humidity
In Grangeville, the average relative humidity in September is 53%.Rainfall
In Grangeville, in September, it is raining for 7.8 days, with typically 0.94" (24mm) of accumulated precipitation. Throughout the year, in Grangeville, there are 146.2 rainfall days, and 23.35" (593mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows in Grangeville. Throughout September, in the average 0.3 snowfall days, it receives 0.75" (19mm) of snow. In Grangeville, during the entire year, snow falls for 80.3 days and aggregates up to 60.47" (1536mm) of snow.Daylight
In Grangeville, Idaho, the average length of the day in September is 12h and 31min.On the first day of September in Grangeville, sunrise is at 6:06 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:25 pm PDT.
Sunshine
In September, the average sunshine is 10h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: The daily high UV index of 4 during September translates into the following recommendations:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Frequently asked questions
What are the temperatures in Grangeville in September?
What is the average humidity in September in Grangeville?
How many days does it rain in September in Grangeville?
When does it start to snow in Grangeville?
How many hours of daylight does Grangeville have in September?
What time are sunrise and sunset in September in Grangeville?
How long on average sun shines in September in Grangeville?
What is the UV index reading in September in Grangeville?
Average temperature in September
Grangeville, ID
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is August (82.6°F).
The month with the lowest average high temperature is December (33.6°F).
- Average low temperature in September: 47.3°F
The month with the highest average low temperature is August (53.2°F).
The coldest month (with the lowest average low temperature) is December (21.7°F).
Average pressure in September
Grangeville, ID
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.21"Hg).
The months with the lowest atmospheric pressure are June and August (29.94"Hg).
Average wind speed in September
Grangeville, ID
- Average wind speed in September: 3.9mph
The windiest months (with the highest average wind speed) are January and November (4.9mph).
The calmest month (with the lowest average wind speed) is August (3.8mph).
Average humidity in September
Grangeville, ID
- Average humidity in September: 53%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is August (47%).
Average rainfall in September
Grangeville, ID
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is April (2.91").
The driest month (with the least rainfall) is July (0.59").
Average rainfall days in September
Grangeville, ID
- Average rainfall days in September: 7.8 days
The month with the highest number of rainy days is April (19.3 days).
The month with the least rainy days is August (6.8 days).
Average snowfall in September
Grangeville, ID
- Average snowfall in September: 0.75"
The month with the highest snowfall is February (12.95").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Grangeville, ID
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is December (16.9 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Grangeville, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 10h and 0min
The month with the most sunshine is August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).
Average sunshine days in September
Grangeville, ID
- Average sunshine days in September: 20 days
The month with the most sunshine days is August (22.2 days).
The month with the least sunshine days is March (7.5 days).
Average UV index in September
Grangeville, ID
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Grangeville, ID
- Average cloud cover in September: 21
The month with the most cloud cover is February (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Grangeville, ID
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (4mi).
Grangeville, Idaho, USA
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