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's arrival coincides with a drop in the average high-temperature, decreasing from August's tropical 86.9°F (30.5°C) to a warm 76.1°F (24.5°C). Nightly readings in September display a noticeable downturn from daily highs, with the average low-temperature registering a fresh 53.8°F (12.1°C).Humidity
In Declo, the average relative humidity in September is 35%.Rainfall
In Declo, in September, during 6.3 rainfall days, 0.43" (11mm) of precipitation is typically accumulated. In Declo, during the entire year, the rain falls for 105.2 days and collects up to 10.63" (270mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.16" (4mm) of snow. Throughout the year, there are 50.9 snowfall days, and 24.57" (624mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 7:00 am and sunset at 8:08 pm. On the last day of September, sunrise is at 7:31 am and sunset at 7:16 pm MDT.
Sunshine
The average sunshine in September is 9.6h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
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 much does it rain in September?
When does it start snowing?
How many hours of daylight does Declo have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Declo have in September?
What is the UV index intensity in September?
Average temperature in September
Declo, ID
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (32.5°F).
- Average low temperature in September: 53.8°F
The months with the highest average low temperature are July and August (60.8°F).
The coldest month (with the lowest average low temperature) is December (21.6°F).
Average pressure in September
Declo, ID
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Declo, ID
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (9.8mph).
The calmest month (with the lowest average wind speed) is January (7.1mph).
Average humidity in September
Declo, ID
- Average humidity in September: 35%
The month with the highest relative humidity is January (80%).
The months with the lowest relative humidity are July and August (30%).
Average rainfall in September
Declo, ID
- Average rainfall in September: 0.43"
The wettest month (with the highest rainfall) is March (1.46").
The driest month (with the least rainfall) is July (0.28").
Average rainfall days in September
Declo, ID
- Average rainfall days in September: 6.3 days
The months with the highest number of rainy days are March and April (14 days).
The months with the least rainy days are July and August (5.2 days).
Average snowfall in September
Declo, ID
- Average snowfall in September: 0.16"
The month with the highest snowfall is December (6.54").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Declo, ID
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (13 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Declo, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 42min).
Average sunshine days in September
Declo, ID
- Average sunshine days in September: 21.6 days
The month with the most sunshine days is July (22.6 days).
The month with the least sunshine days is March (12 days).
Average UV index in September
Declo, ID
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Declo, ID
- Average cloud cover in September: 14
The month with the most cloud cover is December (Cloud cover 40).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Declo, ID
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Declo, Idaho, USA
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