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 brings a minor shift in the average high-temperature, adjusting from 81.1°F (27.3°C) in August to a still moderately hot 75.2°F (24°C). The low-temperature averages to a refreshing 56.3°F (13.5°C) during the nights of September.Humidity
The average relative humidity in September is 76%.Rainfall
In Keswick, in September, during 12.1 rainfall days, 2.76" (70mm) of precipitation is typically accumulated. Throughout the year, there are 137.9 rainfall days, and 27.76" (705mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:41 pm. On the last day of September, sunrise is at 7:05 am and sunset at 6:51 pm CDT.
Sunshine
In September, the average sunshine is 9.4h.UV index
In Keswick, 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 the average person.Note: The maximum daily UV index of 4 during September translates into the following directions:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September in Keswick?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Keswick, IA
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (28.6°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (15.6°F).
Average pressure in September
Keswick, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Keswick, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).
Average humidity in September
Keswick, IA
- Average humidity in September: 76%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Keswick, IA
- Average rainfall in September: 2.76"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in September
Keswick, IA
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (4.9 days).
Average snowfall in September
Keswick, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.06").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Keswick, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Keswick, IA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Keswick, IA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is December (19.1 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Keswick, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in September
Keswick, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility in September
Keswick, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Keswick, Iowa, USA
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