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 shift to September brings a decrease in the average high-temperature, falling from a warm 78.4°F (25.8°C) in August to an enjoyable 67.1°F (19.5°C). A pronounced dip becomes evident during the nights in September as Dayton logs a consistent average temperature of 41.5°F (5.3°C).Humidity
The average relative humidity in September is 61%.Rainfall
In Dayton, in September, it is raining for 10.2 days, with typically 0.98" (25mm) of accumulated precipitation. Throughout the year, there are 129.8 rainfall days, and 16.42" (417mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.4 snowfall days, it receives 0.2" (5mm) of snow. Throughout the year, in Dayton, there are 117.4 snowfall days, and 58.62" (1489mm) of snow is accumulated.Daylight
In Dayton, the average length of the day in September is 12h and 33min.On the first day of the month, sunrise is at 6:56 am and sunset at 8:17 pm. On the last day of September, sunrise is at 7:36 am and sunset at 7:17 pm MDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 3 in September translates into these instructions:
Adopt protective measures - It is advised to guard against sun damage. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. On your guard! Snow's reflection can almost 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 is the usual temperature for Dayton in September?
What is the average humidity in September?
How much does it rain in September?
When does it start to snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Dayton have in September?
What is the UV index reading in September?
Average temperature in September
Dayton, MT
- Average high temperature in September: 67.1°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is December (27.1°F).
- Average low temperature in September: 41.5°F
The month with the highest average low temperature is July (48.4°F).
The coldest months (with the lowest average low temperature) are January and December (16.2°F).
Average pressure in September
Dayton, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Dayton, MT
- Average wind speed in September: 3.7mph
The windiest month (with the highest average wind speed) is April (4.7mph).
The calmest months (with the lowest average wind speed) are August and December (3.6mph).
Average humidity in September
Dayton, MT
- Average humidity in September: 61%
The month with the highest relative humidity is January (93%).
The months with the lowest relative humidity are July and August (52%).
Average rainfall in September
Dayton, MT
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is July (0.59").
Average rainfall days in September
Dayton, MT
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is April (15.9 days).
The month with the least rainy days is December (6.5 days).
Average snowfall in September
Dayton, MT
- Average snowfall in September: 0.2"
The month with the highest snowfall is December (12.36").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Dayton, MT
- Average snowfall days in September: 0.4 days
The month with the highest number of snowfall days is January (22.3 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Dayton, MT
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Dayton, MT
- Average sunshine days in September: 18.6 days
The month with the most sunshine days is July (20.8 days).
The month with the least sunshine days is February (7.1 days).
Average UV index in September
Dayton, MT
- Average UV index in September: 3
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 1).
Average cloud cover in September
Dayton, MT
- Average cloud cover in September: 25
The month with the most cloud cover is January (Cloud cover 64).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in September
Dayton, MT
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The month with the lowest visibility is January (3mi).
Dayton, Montana, USA
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