September weather forecastCorvallis, MT
September
Weather in September
September, the first month of the autumn in Corvallis, is also an enjoyable month, with temperature in the range of an average low of 39.9°F (4.4°C) and an average high of 66.2°F (19°C).Temperature
September's arrival corresponds with a decrease in average high-temperatures, from August's moderately hot 76.3°F (24.6°C) to a comfortable 66.2°F (19°C). Despite soaring daytime temperatures, Corvallis registers a consistent average low-temperature of 39.9°F (4.4°C) in September.Humidity
In September, the average relative humidity in Corvallis, Montana, is 57%.Rainfall
In Corvallis, in September, during 9.9 rainfall days, 0.98" (25mm) of precipitation is typically accumulated. In Corvallis, during the entire year, the rain falls for 163.6 days and collects up to 20.83" (529mm) of precipitation.Snowfall
Months with snowfall in Corvallis are January through May, September through December. September is the first month it typically snows in Corvallis. Throughout September, in the average 0.4 snowfall days, it receives 0.55" (14mm) of snow. Throughout the year, there are 101.1 snowfall days, and 59.17" (1503mm) of snow is accumulated.Daylight
In Corvallis, the average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:57 am and sunset at 8:14 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 7:17 pm MDT.
Sunshine
In Corvallis, the average sunshine in September is 9.5h.UV index
In September, the average daily maximum UV index in Corvallis, Montana, is 3. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The UV index of 3 in September translates into these instructions:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Corvallis, MT
- Average high temperature in September: 66.2°F
The warmest month (with the highest average high temperature) is July (77°F).
The month with the lowest average high temperature is December (26.8°F).
- Average low temperature in September: 39.9°F
The month with the highest average low temperature is August (46.9°F).
The coldest month (with the lowest average low temperature) is December (14°F).
Average pressure in September
Corvallis, MT
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.21"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Corvallis, MT
- Average wind speed in September: 4.4mph
The windiest month (with the highest average wind speed) is January (5.3mph).
The calmest month (with the lowest average wind speed) is August (4.1mph).
Average humidity in September
Corvallis, MT
- Average humidity in September: 57%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (50%).
Average rainfall in September
Corvallis, MT
- Average rainfall in September: 0.98"
The wettest months (with the highest rainfall) are February and April (2.36").
The driest month (with the least rainfall) is August (0.75").
Average rainfall days in September
Corvallis, MT
- Average rainfall days in September: 9.9 days
The month with the highest number of rainy days is May (19.5 days).
The month with the least rainy days is July (8 days).
Average snowfall in September
Corvallis, MT
- Average snowfall in September: 0.55"
The month with the highest snowfall is February (13.03").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Corvallis, MT
- Average snowfall days in September: 0.4 days
The month with the highest number of snowfall days is February (19.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Corvallis, 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 42min).
- Average sunshine in September: 9h and 30min
The months with the most sunshine are July and August (Average sunshine: 11h and 42min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).
Average sunshine days in September
Corvallis, MT
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is July (18.9 days).
The month with the least sunshine days is February (5.6 days).
Average UV index in September
Corvallis, MT
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are February and December (UV index 1).
Average cloud cover in September
Corvallis, MT
- Average cloud cover in September: 21
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Corvallis, MT
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March and December (4mi).
