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 marks a decrease in the average high-temperature, transitioning from 85.1°F (29.5°C) in August to a still moderately hot 75.2°F (24°C). During September, the average low-temperature is recorded at a fresh 54.7°F (12.6°C).Humidity
In Garryowen, the average relative humidity in September is 42%.Rainfall
In September, the rain falls for 6.7 days. Throughout September, 1.06" (27mm) of precipitation is accumulated. Throughout the year, there are 103 rainfall days, and 11.97" (304mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow. In Garryowen, Montana, during the entire year, snow falls for 56.7 days and aggregates up to 25.16" (639mm) of snow.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:46 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:51 pm MDT.
Sunshine
In September, the average sunshine is 10.6h.UV index
In Garryowen, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: The maximum UV index, 5 during September, leads to the following recommendations:
Exercise caution. Those with pale skin may experience burns in less than half an hour. To guard against the harmful effects of the Sun, minimize exposure during midday. Experience reduced UV exposure by about half when donning a wide-brim hat. 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 are September temperatures?
What is the average humidity in September?
How much does it rain in September?
When does it start to snow?
How many hours of daylight does Garryowen have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Garryowen, MT
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is December (31.3°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is July (62.8°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).
Average pressure in September
Garryowen, MT
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Garryowen, MT
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).
Average humidity in September
Garryowen, MT
- Average humidity in September: 42%
The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (38%).
Average rainfall in September
Garryowen, MT
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is May (1.81").
The driest month (with the least rainfall) is August (0.63").
Average rainfall days in September
Garryowen, MT
- Average rainfall days in September: 6.7 days
The month with the highest number of rainy days is May (13.6 days).
The month with the least rainy days is December (5.9 days).
Average snowfall in September
Garryowen, MT
- Average snowfall in September: 0.08"
The month with the highest snowfall is February (5.43").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Garryowen, MT
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (12.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Garryowen, MT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 10h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 36min).
Average sunshine days in September
Garryowen, MT
- Average sunshine days in September: 21.5 days
The month with the most sunshine days is September (21.5 days).
The month with the least sunshine days is February (13.3 days).
Average UV index in September
Garryowen, MT
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Garryowen, MT
- Average cloud cover in September: 19
The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is July (Cloud cover 13).
Average visibility in September
Garryowen, MT
- 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).
Garryowen, Montana, USA
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