September weather forecastHarrison, MT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Harrison, Montana, with temperature in the range of an average high of 70.9°F (21.6°C) and an average low of 44.4°F (6.9°C).Temperature
September comes with a drop in the average high-temperature, falling from August's moderately hot 81.9°F (27.7°C) to a pleasant 70.9°F (21.6°C). Harrison sees a large disparity in day to night temperatures in September, with the night temperature dropping to an average of 44.4°F (6.9°C).Humidity
In Harrison, the average relative humidity in September is 49%.Rainfall
In September, the rain falls for 8.4 days. Throughout September, 0.91" (23mm) of precipitation is accumulated. Throughout the year, there are 134.2 rainfall days, and 11.34" (288mm) 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 0.5 snowfall days, it receives 0.83" (21mm) of snow. Throughout the year, there are 79.6 snowfall days, and 30.08" (764mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 31min.On the first day of September in Harrison, sunrise is at 6:49 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 7:08 pm MDT.
Sunshine
The average sunshine in September is 10h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum UV index of 3 during September translates into these guidelines:
Guard yourself - An obligation to protect skin and eyes from harm exists. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Harrison, MT
- Average high temperature in September: 70.9°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is December (28°F).
- Average low temperature in September: 44.4°F
The month with the highest average low temperature is August (50.5°F).
The coldest month (with the lowest average low temperature) is December (12.7°F).
Average pressure in September
Harrison, MT
- Average pressure in September: 29.98"Hg
The months with the highest atmospheric pressure are January and December (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Harrison, MT
- Average wind speed in September: 4.6mph
The windiest month (with the highest average wind speed) is April (5.5mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity in September
Harrison, MT
- Average humidity in September: 49%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is August (44%).
Average rainfall in September
Harrison, MT
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is June (1.57").
The driest month (with the least rainfall) is August (0.51").
Average rainfall days in September
Harrison, MT
- Average rainfall days in September: 8.4 days
The month with the highest number of rainy days is April (16.5 days).
The month with the least rainy days is August (7.6 days).
Average snowfall in September
Harrison, MT
- Average snowfall in September: 0.83"
The month with the highest snowfall is February (6.02").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Harrison, MT
- Average snowfall days in September: 0.5 days
The month with the highest number of snowfall days is February (16.5 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Harrison, MT
- Average daylight in September: 12h and 30min
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 48min).
- Average sunshine in September: 10h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 5h and 54min).
Average sunshine days in September
Harrison, MT
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is September (18.7 days).
The month with the least sunshine days is April (9.3 days).
Average UV index in September
Harrison, 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 December (UV index 1).
Average cloud cover in September
Harrison, MT
- Average cloud cover in September: 20
The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Harrison, MT
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).
