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
Stepping into September, Dedham records an average high-temperature of a still moderately hot 74.7°F (23.7°C), almost consistent with August. The temperature lowers to an average of 55.8°F (13.2°C) during September nights.Humidity
The average relative humidity in September is 75%.Rainfall
In September, the rain falls for 10.9 days. Throughout September, 2.72" (69mm) of precipitation is accumulated. Throughout the year, there are 130.1 rainfall days, and 27.28" (693mm) 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 6:45 am and sunset at 7:52 pm. On the last day of September, sunrise is at 7:15 am and sunset at 7:02 pm CDT.
Sunshine
The average sunshine in September is 9.2h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: In September, an average UV index of 4 transforms into the following instructions:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
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?
How many hours of daylight does Dedham have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Dedham have in September?
What is the UV index intensity in September?
Average temperature in September
Dedham, IA
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (26.2°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (13.6°F).
Average pressure in September
Dedham, IA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Dedham, IA
- Average wind speed in September: 8.5mph
The windiest month (with the highest average wind speed) is January (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in September
Dedham, IA
- Average humidity in September: 75%
The month with the highest relative humidity is January (84%).
The months with the lowest relative humidity are April and October (69%).
Average rainfall in September
Dedham, IA
- Average rainfall in September: 2.72"
The wettest month (with the highest rainfall) is May (4.29").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in September
Dedham, IA
- Average rainfall days in September: 10.9 days
The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (4.3 days).
Average snowfall in September
Dedham, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.12").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Dedham, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Dedham, IA
- 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 12min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Dedham, IA
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is June (10 days).
Average UV index in September
Dedham, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Dedham, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Dedham, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, September, October, November and December (6mi).
The months with the lowest visibility are January and August (5mi).
Dedham, Iowa, USA
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