September weather forecastWatterson, IA
September
Weather in September
The first month of the autumn, September, is still a warm month in Watterson, Iowa, with an average temperature varying between 75.9°F (24.4°C) and 56.3°F (13.5°C).Temperature
The start of September involves a subtle temperature drop, shifting from 81.7°F (27.6°C) in August to a still warm 75.9°F (24.4°C). An average minimum temperature of 56.3°F (13.5°C) marks the month of September in Watterson.Humidity
In September, the average relative humidity is 76%.Rainfall
In Watterson, in September, during 11 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. Throughout the year, there are 126.9 rainfall days, and 22.6" (574mm) of precipitation is accumulated.Snowfall
In Watterson, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:44 am and sunset at 7:48 pm. On the last day of September, in Watterson, sunrise is at 7:13 am and sunset at 7:00 pm CDT.
Sunshine
The average sunshine in September is 9.3h.UV index
In September, the average daily maximum UV index in Watterson is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Take precautions - Protection against sunburn is recommended. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Boost your sun resistance with garments that are densely woven yet spacious.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Watterson, IA
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).
Average pressure in September
Watterson, 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
Watterson, IA
- Average wind speed in September: 7.8mph
The windiest months (with the highest average wind speed) are January, February and March (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Watterson, IA
- Average humidity in September: 76%
The month with the highest relative humidity is June (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Watterson, IA
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is June (3.86").
The driest months (with the least rainfall) are February and December (0.71").
Average rainfall days in September
Watterson, IA
- Average rainfall days in September: 11 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Watterson, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.54").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Watterson, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Watterson, IA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 18min
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 36min).
Average sunshine days in September
Watterson, IA
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is November (21.2 days).
The month with the least sunshine days is May (10.6 days).
Average UV index in September
Watterson, IA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Watterson, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Watterson, 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).
