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
As August transitions into September, Washington sees a gentle drop in the average high-temperature, transitioning from a tropical 87.1°F (30.6°C) to a moderately hot 80.1°F (26.7°C). An average low-temperature of 59.2°F (15.1°C) is observed during September nights in Washington, Missouri.Humidity
In Washington, the average relative humidity in September is 74%.Rainfall
In Washington, in September, it is raining for 11 days, with typically 1.89" (48mm) of accumulated precipitation. Throughout the year, there are 133.1 rainfall days, and 27.24" (692mm) of precipitation is accumulated.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 Washington, Missouri, during the entire year, snow falls for 16.6 days and aggregates up to 5.87" (149mm) of snow.Daylight
In Washington, Missouri, the average length of the day in September is 12h and 25min.On the first day of September in Washington, sunrise is at 6:34 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:47 pm CDT.
Sunshine
In Washington, the average sunshine in September is 9.4h.UV index
In Washington, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 5 during September translates into the following guidance:
Act with care - The need to guard against sun damage is communicated. Around midday, solar radiation is most harmful; hence, exposure should be limited. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Frequently asked questions
What is the temperature in September in Washington?
What is the average humidity in September in Washington?
How many days does it rain in September in Washington?
When does it start to snow in Washington?
What is the average length of the day in September in Washington?
When is the sunrise / sunset in September in Washington?
How long on average sun shines in September in Washington?
What is the UV index reading in September in Washington?
Average temperature in September
Washington, MO
- Average high temperature in September: 80.1°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is January (38.1°F).
- Average low temperature in September: 59.2°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (24.1°F).
Average pressure in September
Washington, MO
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Washington, MO
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is January (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in September
Washington, MO
- Average humidity in September: 74%
The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Washington, MO
- Average rainfall in September: 1.89"
The wettest months (with the highest rainfall) are April and May (3.23").
The driest month (with the least rainfall) is February (1.42").
Average rainfall days in September
Washington, MO
- Average rainfall days in September: 11 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is January (6.2 days).
Average snowfall in September
Washington, MO
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (2.09").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in September
Washington, MO
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (5.1 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Washington, MO
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in September
Washington, MO
- Average sunshine days in September: 17 days
The month with the most sunshine days is December (20.6 days).
The month with the least sunshine days is May (12.8 days).
Average UV index in September
Washington, MO
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Washington, MO
- Average cloud cover in September: 32
The months with the most cloud cover are January and February (Cloud cover 50).
The months with the least cloud cover are June, July and August (Cloud cover 30).
Average visibility in September
Washington, MO
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, September, October, November and December (6mi).
The months with the lowest visibility are May and August (5mi).
Washington, Missouri, USA
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