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 brings a decrease in the average high-temperature, shifting from a moderately hot 77.9°F (25.5°C) in August to a comfortable 67.1°F (19.5°C). In the face of high daytime temperatures, Greenough witnesses a consistent average nighttime low of 39.7°F (4.3°C) during September.Humidity
The average relative humidity in September is 57%.Rainfall
In Greenough, in September, during 2.8 rainfall days, 0.2" (5mm) of precipitation is typically accumulated. Throughout the year, there are 46.4 rainfall days, and 2.4" (61mm) 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 0.3 snowfall days, it receives 0.43" (11mm) of snow. In Greenough, during the entire year, snow falls for 31.4 days and aggregates up to 7.64" (194mm) of snow.Daylight
The average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:54 am and sunset at 8:12 pm. On the last day of the month, sunrise is at 7:32 am and sunset at 7:14 pm MDT.
Sunshine
The average sunshine in September is 9.8h.UV index
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:
Act with care - The suggestion to avoid sunburn is emphasized. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
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?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Greenough have in September?
How high is the UV index in September?
Average temperature in September
Greenough, MT
- Average high temperature in September: 67.1°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is December (26.1°F).
- Average low temperature in September: 39.7°F
The months with the highest average low temperature are July and August (45.5°F).
The coldest month (with the lowest average low temperature) is December (12.2°F).
Average pressure in September
Greenough, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Greenough, MT
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is April (6mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Greenough, MT
- Average humidity in September: 57%
The month with the highest relative humidity is January (91%).
The months with the lowest relative humidity are July and August (51%).
Average rainfall in September
Greenough, MT
- Average rainfall in September: 0.2"
The wettest month (with the highest rainfall) is June (0.43").
The driest month (with the least rainfall) is December (0.08").
Average rainfall days in September
Greenough, MT
- Average rainfall days in September: 2.8 days
The month with the highest number of rainy days is April (6.8 days).
The month with the least rainy days is January (2.3 days).
Average snowfall in September
Greenough, MT
- Average snowfall in September: 0.43"
The month with the highest snowfall is February (1.57").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Greenough, MT
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (5.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Greenough, MT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 9h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 12min).
Average sunshine days in September
Greenough, MT
- Average sunshine days in September: 26.7 days
The month with the most sunshine days is July (27 days).
The month with the least sunshine days is April (21.9 days).
Average UV index in September
Greenough, MT
- Average UV index in September: 3
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Greenough, MT
- Average cloud cover in September: 19
The months with the most cloud cover are January and February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 12).
Average visibility in September
Greenough, MT
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).
Greenough, Montana, USA
Weather forecast for your location
2. Allow the app to use your location