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
During the shift to September, a minor reduction in average high-temperature is observed, shifting from 81.7°F (27.6°C) in August to a still moderately hot 75.7°F (24.3°C). In Ottumwa, the average temperature during the nights of September drops to a moderate 56.5°F (13.6°C).Humidity
The average relative humidity in September in Ottumwa is 76%.Rainfall
In September, the rain falls for 11.7 days. Throughout September, 2.76" (70mm) of precipitation is accumulated. In Ottumwa, during the entire year, the rain falls for 134.5 days and collects up to 27.17" (690mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:41 pm. On the last day of September, in Ottumwa, sunrise is at 7:06 am and sunset at 6:52 pm CDT.
Sunshine
In September, the average sunshine in Ottumwa, Iowa, is 9.4h.UV index
In Ottumwa, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Ensure safety - Sun damage prevention is strongly urged. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. 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 in Ottumwa?
What is the average humidity in September in Ottumwa?
How much does it rain in Ottumwa in September?
When it does not snow in Ottumwa?
Does it snow in Ottumwa in September?
How many hours of daylight does Ottumwa have in September?
When is the sunrise / sunset in September in Ottumwa?
How many hours of sunshine does Ottumwa have in September?
What is the UV index intensity in September in Ottumwa?
Average temperature in September
Ottumwa, IA
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in September
Ottumwa, 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
Ottumwa, IA
- Average wind speed in September: 7.9mph
The windiest month (with the highest average wind speed) is January (10.8mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).
Average humidity in September
Ottumwa, IA
- Average humidity in September: 76%
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Ottumwa, IA
- Average rainfall in September: 2.76"
The wettest month (with the highest rainfall) is May (4.02").
The driest month (with the least rainfall) is January (1.06").
Average rainfall days in September
Ottumwa, IA
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (5.2 days).
Average snowfall in September
Ottumwa, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.17").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Ottumwa, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Ottumwa, 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 18min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Ottumwa, IA
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is December (18.9 days).
The month with the least sunshine days is May (11.6 days).
Average UV index in September
Ottumwa, IA
- Average UV index in September: 4
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
Ottumwa, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility in September
Ottumwa, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Ottumwa, Iowa, USA
Weather forecast for your location
2. Allow the app to use your location