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's onset brings a reduction in the average high-temperature, from a warm 77.5°F (25.3°C) in August to a comfortable 67.5°F (19.7°C). September nights present a sharp contrast to daytime highs, with average temperatures of 42.4°F (5.8°C).Humidity
The average relative humidity in September is 52%.Rainfall
In Jefferson City, in September, during 9.8 rainfall days, 1.14" (29mm) of precipitation is typically accumulated. In Jefferson City, during the entire year, the rain falls for 133.7 days and collects up to 16.38" (416mm) of precipitation.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 1.2 snowfall days, it receives 2.01" (51mm) of snow. In Jefferson City, during the entire year, snow falls for 105.8 days and aggregates up to 55.12" (1400mm) of snow.Daylight
The average length of the day in September is 12h and 32min.On the first day of the month, sunrise is at 6:49 am and sunset at 8:06 pm. On the last day of September, in Jefferson City, sunrise is at 7:26 am and sunset at 7:09 pm MDT.
Sunshine
In Jefferson City, the average sunshine in September is 9.8h.UV index
In Jefferson City, the average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 3 in September converts into the following recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Jefferson City 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?
What time are sunrise and sunset in September?
How many hours of sunshine does Jefferson City have in September?
What is the UV index reading in September?
Average temperature in September
Jefferson City, MT
- Average high temperature in September: 67.5°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is December (27°F).
- Average low temperature in September: 42.4°F
The month with the highest average low temperature is August (48.6°F).
The coldest month (with the lowest average low temperature) is December (12.6°F).
Average pressure in September
Jefferson City, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Jefferson City, MT
- Average wind speed in September: 5.4mph
The windiest months (with the highest average wind speed) are January and November (6.5mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Jefferson City, MT
- Average humidity in September: 52%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is August (46%).
Average rainfall in September
Jefferson City, MT
- Average rainfall in September: 1.14"
The wettest month (with the highest rainfall) is June (2.68").
The driest month (with the least rainfall) is December (0.79").
Average rainfall days in September
Jefferson City, MT
- Average rainfall days in September: 9.8 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is November (7.5 days).
Average snowfall in September
Jefferson City, MT
- Average snowfall in September: 2.01"
The month with the highest snowfall is February (9.72").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Jefferson City, MT
- Average snowfall days in September: 1.2 days
The month with the highest number of snowfall days is February (18 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Jefferson City, MT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 9h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The months with the least sunshine are January and December (Average sunshine: 5h and 36min).
Average sunshine days in September
Jefferson City, MT
- Average sunshine days in September: 17.9 days
The month with the most sunshine days is September (17.9 days).
The month with the least sunshine days is February (8.5 days).
Average UV index in September
Jefferson City, MT
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Jefferson City, MT
- Average cloud cover in September: 22
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility in September
Jefferson City, MT
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
Jefferson City, Montana, USA
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