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
The onset of September is marked by a decrease in temperature, transitioning from a hot 86.2°F (30.1°C) in August to a warm 75.4°F (24.1°C). Throughout September, an average low-temperature of 54.3°F (12.4°C) is expected.Humidity
The average relative humidity in September is 46%.Rainfall
In Alfalfa, Washington, in September, during 4.8 rainfall days, 0.16" (4mm) of precipitation is typically accumulated. In Alfalfa, during the entire year, the rain falls for 78 days and collects up to 3.39" (86mm) of precipitation.Snowfall
Months with snowfall are January through March, September, November and December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Alfalfa, during the entire year, snow falls for 14.9 days and aggregates up to 3.11" (79mm) of snow.Daylight
In Alfalfa, the average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:22 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:42 pm PDT.
Sunshine
In Alfalfa, the average sunshine in September is 11h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Prioritize safety - Recommendations to avert sunburn are shared. When the Sun is at its strongest around midday, find shade and limit exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Be vigilant! The reflective nature of snow can increase the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Alfalfa?
What is the average humidity in September?
How many days does it rain in September?
When does it start snowing?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Alfalfa have in September?
How high is the UV index in September?
Average temperature in September
Alfalfa, WA
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is December (36.5°F).
- Average low temperature in September: 54.3°F
The month with the highest average low temperature is August (60.8°F).
The coldest month (with the lowest average low temperature) is December (25.5°F).
Average pressure in September
Alfalfa, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is August (29.92"Hg).
Average wind speed in September
Alfalfa, WA
- Average wind speed in September: 6.4mph
The windiest month (with the highest average wind speed) is April (7.9mph).
The calmest month (with the lowest average wind speed) is December (4.8mph).
Average humidity in September
Alfalfa, WA
- Average humidity in September: 46%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is July (38%).
Average rainfall in September
Alfalfa, WA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is May (0.63").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in September
Alfalfa, WA
- Average rainfall days in September: 4.8 days
The month with the highest number of rainy days is March (9.9 days).
The months with the least rainy days are July and August (2.8 days).
Average snowfall in September
Alfalfa, WA
- Average snowfall in September: 0.04"
The months with the highest snowfall are January, February and December (0.94").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in September
Alfalfa, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (4.7 days).
The months with the least snowfall days are April, May, June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Alfalfa, WA
- 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: 11h and 0min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 18min).
Average sunshine days in September
Alfalfa, WA
- Average sunshine days in September: 22.7 days
The month with the most sunshine days is July (26.6 days).
The month with the least sunshine days is March (17.3 days).
Average UV index in September
Alfalfa, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Alfalfa, WA
- Average cloud cover in September: 16
The month with the most cloud cover is January (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Alfalfa, WA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).
Alfalfa, Washington, USA
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