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
The beginning of September in Riverton marks a decrease in the average high-temperature, transitioning from a moderately hot 84.9°F (29.4°C) in August to a still warm 75.6°F (24.2°C). Riverton measures a considerable dip from daytime highs with an average low-temperature of 52.9°F (11.6°C) during September.Humidity
In Riverton, the average relative humidity in September is 35%.Rainfall
In Riverton, in September, during 6 rainfall days, 0.55" (14mm) of precipitation is typically accumulated. Throughout the year, there are 67.3 rainfall days, and 6.93" (176mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.63" (16mm) of snow. In Riverton, Wyoming, during the entire year, snow falls for 42.8 days and aggregates up to 25.47" (647mm) of snow.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:55 pm MDT.
Sunshine
The average sunshine in September is 10.7h.UV index
In Riverton, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.Note: In September, an average UV index of 4 transforms into the following instructions:
Exercise prevention - Warding off sunburn is urged. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How much does it rain in September?
When does it start snowing?
How many hours of daylight does Riverton have in September?
When are sunrise and sunset in September in Riverton?
How many hours of sunshine does Riverton have in September?
What is the UV index intensity in September?
Average temperature in September
Riverton, WY
- Average high temperature in September: 75.6°F
The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is December (30.9°F).
- Average low temperature in September: 52.9°F
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (14.5°F).
Average pressure in September
Riverton, WY
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Riverton, WY
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is June (7.5mph).
The calmest month (with the lowest average wind speed) is January (5.5mph).
Average humidity in September
Riverton, WY
- Average humidity in September: 35%
The month with the highest relative humidity is January (77%).
The months with the lowest relative humidity are July and August (31%).
Average rainfall in September
Riverton, WY
- Average rainfall in September: 0.55"
The wettest month (with the highest rainfall) is May (1.42").
The driest month (with the least rainfall) is January (0.24").
Average rainfall days in September
Riverton, WY
- Average rainfall days in September: 6 days
The month with the highest number of rainy days is May (9.9 days).
The month with the least rainy days is January (2.5 days).
Average snowfall in September
Riverton, WY
- Average snowfall in September: 0.63"
The month with the highest snowfall is April (5.39").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Riverton, WY
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (7.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Riverton, WY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 10h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 6h and 36min).
Average sunshine days in September
Riverton, WY
- Average sunshine days in September: 20.2 days
The month with the most sunshine days is January (24.5 days).
The month with the least sunshine days is April (15.5 days).
Average UV index in September
Riverton, WY
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Riverton, WY
- Average cloud cover in September: 13
The months with the most cloud cover are February and April (Cloud cover 28).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in September
Riverton, WY
- 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).
Riverton, Wyoming, USA
Weather forecast for your location
2. Allow the app to use your location