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
September shows a mild decline in the average high-temperature, falling from August's agreeable 71.4°F (21.9°C) to a comfortable 61.9°F (16.6°C). In September, Riverside experiences a significant drop from daily zeniths to an average nighttime temperature of 37.6°F (3.1°C).Humidity
In Riverside, the average relative humidity in September is 57%.Rainfall
In Riverside, Montana, in September, it is raining for 10.5 days, with typically 1.57" (40mm) of accumulated precipitation. Throughout the year, there are 109.2 rainfall days, and 23.15" (588mm) of precipitation is accumulated.Snowfall
January through July, September through December are months with snowfall in Riverside. September is the first month it typically snows in Riverside. Throughout September, in the average 2.4 snowfall days, it receives 3.27" (83mm) of snow. Throughout the year, there are 159.3 snowfall days, and 120.47" (3060mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 30min.On the first day of September, sunrise is at 6:47 am and sunset at 8:00 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 7:06 pm MDT.
Sunshine
In September, the average sunshine is 9.8h.UV index
In Riverside, the average daily maximum UV index in September is 2. A UV Index estimate of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: The daily maximum UV index of 2 in September interprets into the following advice:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Always opt for UVA and UVB-resistant sunglasses on radiant days. Be alert to the fact! The reflection from snow can nearly double the UV radiation of the Sun.
Frequently asked questions
What is the temperature in September in Riverside?
What is the average humidity in September in Riverside?
How many days does it rain in September in Riverside?
When does it start to snow in Riverside?
What is the average length of the day in September in Riverside?
When is the sunrise / sunset in September in Riverside?
How long on average sun shines in September in Riverside?
How high is the UV index in September in Riverside?
Average temperature in September
Riverside, MT
- Average high temperature in September: 61.9°F
The warmest month (with the highest average high temperature) is July (72.9°F).
The month with the lowest average high temperature is December (20.1°F).
- Average low temperature in September: 37.6°F
The month with the highest average low temperature is August (43.7°F).
The coldest month (with the lowest average low temperature) is December (4.8°F).
Average pressure in September
Riverside, MT
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.24"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Riverside, MT
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is June (6.8mph).
The calmest month (with the lowest average wind speed) is August (5.8mph).
Average humidity in September
Riverside, MT
- Average humidity in September: 57%
The month with the highest relative humidity is February (95%).
The month with the lowest relative humidity is August (50%).
Average rainfall in September
Riverside, MT
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is May (2.8").
The driest month (with the least rainfall) is July (0.91").
Average rainfall days in September
Riverside, MT
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (2.2 days).
Average snowfall in September
Riverside, MT
- Average snowfall in September: 3.27"
The month with the highest snowfall is February (17.83").
The month with the least snowfall is August (0").
Average snowfall days in September
Riverside, MT
- Average snowfall days in September: 2.4 days
The month with the highest number of snowfall days is March (24.4 days).
The months with the least snowfall days are July and August (0.2 days).
Average daylight in September /
Average sunshine in September
Riverside, MT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 9h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The months with the least sunshine are January, February and December (Average sunshine: 3h and 18min).
Average sunshine days in September
Riverside, MT
- Average sunshine days in September: 14.7 days
The months with the most sunshine days are July and September (14.7 days).
The month with the least sunshine days is February (5.3 days).
Average UV index in September
Riverside, MT
- Average UV index in September: 2
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 1).
Average cloud cover in September
Riverside, MT
- Average cloud cover in September: 22
The month with the most cloud cover is February (Cloud cover 76).
The month with the least cloud cover is July (Cloud cover 16).
Average visibility in September
Riverside, MT
- Average visibility in September: 6mi
The months with the highest visibility are June, July, August and September (6mi).
The months with the lowest visibility are January, February, March and December (3mi).
Riverside, Montana, USA
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