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 in Challis, Idaho, indicates a shift in the average high-temperature, from August's warm 75.4°F (24.1°C) to a comfortable 65.7°F (18.7°C). Despite a significant deviation from daily highs, September sees an average nighttime temperature of 41.5°F (5.3°C) in Challis.Humidity
In Challis, the average relative humidity in September is 45%.Rainfall
In Challis, during September, the rain falls for 6.9 days and regularly aggregates up to 0.51" (13mm) of precipitation. Throughout the year, there are 75.7 rainfall days, and 6.38" (162mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows in Challis, Idaho. Throughout September, in the average 0.5 snowfall days, it receives 0.67" (17mm) of snow. Throughout the year, in Challis, there are 51.7 snowfall days, and 18.62" (473mm) of snow is accumulated.Daylight
In September, the average length of the day in Challis is 12h and 30min.On the first day of the month, sunrise is at 7:00 am and sunset at 8:12 pm. On the last day of September, sunrise is at 7:34 am and sunset at 7:18 pm MDT.
Sunshine
In Challis, the average sunshine in September is 9.5h.UV index
In September, the average daily maximum UV index in Challis, Idaho, is 3. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for average individuals.Note: An average UV index of 3 in September transforms into this advice:
Ensure safety - Recommendations to avert sunburn are presented. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. During bright days, sunglasses that offer UVA and UVB defense are recommended. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Frequently asked questions
What is the average September temperature in Challis?
What is the average humidity in September in Challis?
How much does it rain in Challis in September?
When does it start to snow in Challis?
What is the average length of the day in September in Challis?
When are sunrise and sunset in September in Challis?
How many hours of sunshine does Challis have in September?
What is the UV index reading in September in Challis?
Average temperature in September
Challis, ID
- Average high temperature in September: 65.7°F
The warmest month (with the highest average high temperature) is July (76.6°F).
The month with the lowest average high temperature is December (26.1°F).
- Average low temperature in September: 41.5°F
The month with the highest average low temperature is August (47.8°F).
The coldest month (with the lowest average low temperature) is January (8.1°F).
Average pressure in September
Challis, ID
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Challis, ID
- Average wind speed in September: 5.2mph
The windiest months (with the highest average wind speed) are June and July (5.7mph).
The calmest month (with the lowest average wind speed) is January (4.8mph).
Average humidity in September
Challis, ID
- Average humidity in September: 45%
The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are July and August (38%).
Average rainfall in September
Challis, ID
- Average rainfall in September: 0.51"
The wettest month (with the highest rainfall) is June (1.1").
The driest month (with the least rainfall) is July (0.28").
Average rainfall days in September
Challis, ID
- Average rainfall days in September: 6.9 days
The month with the highest number of rainy days is June (10.2 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in September
Challis, ID
- Average snowfall in September: 0.67"
The month with the highest snowfall is February (3.54").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Challis, ID
- Average snowfall days in September: 0.5 days
The month with the highest number of snowfall days is December (10.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Challis, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 9h and 3min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 48min).
Average sunshine days in September
Challis, ID
- Average sunshine days in September: 21.6 days
The month with the most sunshine days is July (24.1 days).
The months with the least sunshine days are March and April (17.2 days).
Average UV index in September
Challis, ID
- Average UV index in September: 3
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in September
Challis, ID
- Average cloud cover in September: 16
The month with the most cloud cover is February (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in September
Challis, ID
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).
Challis, Idaho, USA
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