September weather forecastRiverton, IA
September
Weather in September
The first month of the autumn, September, is still a warm month in Riverton, Iowa, with an average temperature ranging between max 76.8°F (24.9°C) and min 57.7°F (14.3°C).Temperature
September's onset corresponds with a subtle shift in the average high-temperature, slightly moving from 82.2°F (27.9°C) in August to a still moderately hot 76.8°F (24.9°C). The average low-temperature, in September, is a refreshing 57.7°F (14.3°C).Humidity
In September, the average relative humidity in Riverton is 73%.Rainfall
In September, in Riverton, the rain falls for 12.3 days. Throughout September, 2.32" (59mm) of precipitation is accumulated. In Riverton, Iowa, during the entire year, the rain falls for 125.6 days and collects up to 26.14" (664mm) of precipitation.Snowfall
In Riverton, snow does not fall in May through September.Daylight
In Riverton, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:50 am and sunset at 7:53 pm. On the last day of September, in Riverton, Iowa, sunrise is at 7:18 am and sunset at 7:05 pm CDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: A daily high UV index of 5 in September leads to these guidelines:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Riverton, IA
- Average high temperature in September: 76.8°F
The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (31.3°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (18°F).
Average pressure in September
Riverton, IA
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Riverton, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is July (6.7mph).
Average humidity in September
Riverton, IA
- Average humidity in September: 73%
The months with the highest relative humidity are January and July (79%).
The month with the lowest relative humidity is October (67%).
Average rainfall in September
Riverton, IA
- Average rainfall in September: 2.32"
The wettest month (with the highest rainfall) is June (4.29").
The driest month (with the least rainfall) is February (0.71").
Average rainfall days in September
Riverton, IA
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (3.9 days).
Average snowfall in September
Riverton, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.11").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Riverton, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Riverton, 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 12min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in September
Riverton, IA
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (20.8 days).
The month with the least sunshine days is June (11.8 days).
Average UV index in September
Riverton, IA
- 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
Riverton, IA
- Average cloud cover in September: 28
The month with the most cloud cover is January (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 26).
Average visibility in September
Riverton, 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).
