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 arrival, Downey's weather changes as the average high-temperature falls from a moderately hot 83.7°F (28.7°C) in August to an agreeable 73°F (22.8°C). Despite the intense daytime heat, Downey sustains a steady low-temperature average of 49.5°F (9.7°C) during September.Humidity
The average relative humidity in September in Downey is 42%.Rainfall
In Downey, in September, it is raining for 8.6 days, with typically 1.18" (30mm) of accumulated precipitation. Throughout the year, there are 118.3 rainfall days, and 16.42" (417mm) 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 0.1 snowfall days, it receives 0.35" (9mm) of snow. Throughout the year, there are 68.7 snowfall days, and 48.82" (1240mm) of snow is accumulated.Daylight
In Downey, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:54 am and sunset at 8:01 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:11 pm MDT.
Sunshine
In September, the average sunshine is 9.8h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 4 in September translates into these instructions:
Ensure safety - Recommendations to avert sunburn are presented. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Downey in September?
What is the average humidity in September?
How much does it rain in Downey in September?
When does it start snowing?
How many hours of daylight does Downey have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Downey have in September?
How high is the UV index in September?
Average temperature in September
Downey, ID
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (28.9°F).
- Average low temperature in September: 49.5°F
The month with the highest average low temperature is July (56.3°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).
Average pressure in September
Downey, ID
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.3"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Downey, ID
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is April (6.8mph).
The calmest month (with the lowest average wind speed) is January (4.8mph).
Average humidity in September
Downey, ID
- Average humidity in September: 42%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (35%).
Average rainfall in September
Downey, ID
- Average rainfall in September: 1.18"
The wettest month (with the highest rainfall) is February (2.05").
The driest month (with the least rainfall) is July (0.55").
Average rainfall days in September
Downey, ID
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is January (6.6 days).
Average snowfall in September
Downey, ID
- Average snowfall in September: 0.35"
The month with the highest snowfall is January (13.78").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Downey, ID
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (15.8 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Downey, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 5min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in September
Downey, ID
- Average sunshine days in September: 18.6 days
The month with the most sunshine days is October (19.4 days).
The month with the least sunshine days is February (9.9 days).
Average UV index in September
Downey, 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 January (UV index 1).
Average cloud cover in September
Downey, ID
- Average cloud cover in September: 15
The month with the most cloud cover is February (Cloud cover 52).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Downey, 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, February and December (4mi).
Downey, Idaho, USA
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