September weather forecastRiverton, UT
September
Weather in September
September starts painting a picture of autumn, with visible changes in weather conditions from those experienced in August. The city of Riverton begins its transformation with changing foliage colors. With the highs falling around 74.3°F (23.5°C), there is a significant drop in the intense summer heat. Patterns of moderate rainfall return, leaving a fresh guise over the city. The waning summer gives a clear sign of the steadily creeping chill of October.Temperature
In September, the average high-temperature in Riverton goes from 83.3°F (28.5°C) in August to a still warm 74.3°F (23.5°C). September in Riverton is characterized by a distinct thermal shift, with nighttime lows averaging at a fresh 50.5°F (10.3°C).Humidity
In September, the average relative humidity is 43%.Rainfall
In Riverton, during September, the rain falls for 5.4 days and regularly aggregates up to 0.59" (15mm) of precipitation. In Riverton, during the entire year, the rain falls for 69.6 days and collects up to 9.06" (230mm) of precipitation.Snowfall
In Riverton, snow does not fall in May through September.Daylight
In Riverton, Utah, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:55 am and sunset at 7:59 pm. On the last day of September, sunrise is at 7:24 am and sunset at 7:10 pm MDT.
Sunshine
In September, the average sunshine in Riverton is 10.1h.UV index
In September, the average daily maximum UV index in Riverton is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 4 during September translates into the following directions:
Take necessary precautions - Protection from skin and eye injury is mandatory. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Riverton, UT
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 50.5°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is January (17.1°F).
Average pressure in September
Riverton, UT
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Riverton, UT
- Average wind speed in September: 5.7mph
The windiest months (with the highest average wind speed) are March and April (6.3mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).
Average humidity in September
Riverton, UT
- Average humidity in September: 43%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (37%).
Average rainfall in September
Riverton, UT
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is February (1.38").
The driest month (with the least rainfall) is June (0.31").
Average rainfall days in September
Riverton, UT
- Average rainfall days in September: 5.4 days
The month with the highest number of rainy days is April (8.3 days).
The month with the least rainy days is June (4.1 days).
Average snowfall in September
Riverton, UT
- Average snowfall in September: 0"
The month with the highest snowfall is January (8.27").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Riverton, UT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.7 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, UT
- 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: 10h and 6min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 24min).
Average sunshine days in September
Riverton, UT
- Average sunshine days in September: 23.1 days
The month with the most sunshine days is October (24.9 days).
The month with the least sunshine days is February (17.3 days).
Average UV index in September
Riverton, UT
- Average UV index in September: 4
The month with the highest UV index is July (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, UT
- Average cloud cover in September: 12
The month with the most cloud cover is February (Cloud cover 42).
The month with the least cloud cover is August (Cloud cover 10).
Average visibility in September
Riverton, UT
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).
