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 sea temperature 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 reveals a small adjustment in temperature, transitioning from an average high of a moderately hot 77.7°F (25.4°C) in August to an agreeable 70.3°F (21.3°C). Throughout September, an average low-temperature of 50.4°F (10.2°C) is experienced.Humidity
In September, the average relative humidity in Des Moines is 74%.Rainfall
In Des Moines, in September, it is raining for 10.5 days, with typically 0.91" (23mm) of accumulated precipitation. In Des Moines, during the entire year, the rain falls for 138.2 days and collects up to 14.09" (358mm) of precipitation.Snowfall
April through October are months without snowfall in Des Moines.Ocean temperature
In Des Moines, in September, the average water temperature is 53.4°F (11.9°C).Note: Entering waters of 53.4°F (11.9°C) is life-endangering. A mere moment in 55.4°F (13°C) waters feels piercing cold, and below 50°F (10°C) it can lead to immediate cold shock and cessation of breathing control, depending on body resilience.
Daylight
In September, the average length of the day is 12h and 32min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:48 pm. On the last day of September, sunrise is at 7:08 am and sunset at 6:49 pm PDT.
Sunshine
In Des Moines, the average sunshine in September is 9.2h.UV index
In Des Moines, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Undertake protective steps - Preventing sun damage is advised. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Des Moines in September?
What is the average humidity in September in Des Moines?
How many days does it rain in September in Des Moines?
When it does not snow in Des Moines?
What is the water temperature in September in Des Moines?
What is the average length of the day in September in Des Moines?
When are sunrise and sunset in September in Des Moines?
How long on average sun shines in September in Des Moines?
What is the UV index reading in September in Des Moines?
Average temperature in September
Des Moines, WA
- Average high temperature in September: 70.3°F
The warmest month (with the highest average high temperature) is August (77.7°F).
The month with the lowest average high temperature is December (43.5°F).
- Average low temperature in September: 50.4°F
The month with the highest average low temperature is August (53.6°F).
The coldest month (with the lowest average low temperature) is December (34.3°F).
Average pressure in September
Des Moines, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in September
Des Moines, WA
- Average wind speed in September: 3.9mph
The windiest month (with the highest average wind speed) is March (5.3mph).
The calmest months (with the lowest average wind speed) are July and August (3.6mph).
Average humidity in September
Des Moines, WA
- Average humidity in September: 74%
The months with the highest relative humidity are January and December (85%).
The month with the lowest relative humidity is July (68%).
Average rainfall in September
Des Moines, WA
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is December (2.2").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in September
Des Moines, WA
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is April (14.9 days).
The month with the least rainy days is August (5.7 days).
Average snowfall in September
Des Moines, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.52").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Des Moines, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Des Moines, WA
- Average sea temperature in September: 53.5°F
The best month for swimming (with the highest average sea temperature) is August (53.7°F).
The coldest month (with the lowest average sea temperature) is February (45.8°F).
Average daylight in September /
Average sunshine in September
Des Moines, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 6min).
Average sunshine days in September
Des Moines, WA
- Average sunshine days in September: 17.4 days
The month with the most sunshine days is August (22.8 days).
The month with the least sunshine days is February (13 days).
Average UV index in September
Des Moines, WA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Des Moines, WA
- Average cloud cover in September: 35
The month with the most cloud cover is December (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
Des Moines, WA
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, October, November and December (5mi).
Des Moines, Washington, USA
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