September weather forecastGrass Range, MT
September
Weather in September
September, the first month of the autumn in Grass Range, is still a refreshing month, with temperature in the range of an average low of 47.1°F (8.4°C) and an average high of 67.5°F (19.7°C).Temperature
Grass Range's weather in September involves a decrease in the average high-temperature, moving down from August's moderately hot 78.1°F (25.6°C) to an enjoyable 67.5°F (19.7°C). September in Grass Range generally records an average low-temperature of 47.1°F (8.4°C).Humidity
The average relative humidity in September is 52%.Rainfall
In Grass Range, in September, during 8.7 rainfall days, 1.02" (26mm) of precipitation is typically accumulated. In Grass Range, during the entire year, the rain falls for 126.2 days and collects up to 17.83" (453mm) of precipitation.Snowfall
Months with snowfall in Grass Range, Montana, are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 1 snowfall days, it receives 1.3" (33mm) of snow. In Grass Range, Montana, during the entire year, snow falls for 83.4 days and aggregates up to 45.51" (1156mm) of snow.Daylight
In Grass Range, the average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:35 am and sunset at 7:54 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 6:56 pm MDT.
Sunshine
In September, the average sunshine in Grass Range is 10h.UV index
In Grass Range, Montana, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: The average daily UV index of 4 in September transforms into the following instructions:
Take necessary precautions - Protection from skin and eye injury is mandatory. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Experience reduced UV exposure by about half when donning a wide-brim hat. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grass Range, MT
- Average high temperature in September: 67.5°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The months with the lowest average high temperature are February and December (29.1°F).
- Average low temperature in September: 47.1°F
The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is February (15.3°F).
Average pressure in September
Grass Range, MT
- Average pressure in September: 29.94"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
Grass Range, MT
- Average wind speed in September: 8.5mph
The windiest months (with the highest average wind speed) are January, April and October (9.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).
Average humidity in September
Grass Range, MT
- Average humidity in September: 52%
The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is August (47%).
Average rainfall in September
Grass Range, MT
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is December (0.71").
Average rainfall days in September
Grass Range, MT
- Average rainfall days in September: 8.7 days
The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (5.4 days).
Average snowfall in September
Grass Range, MT
- Average snowfall in September: 1.3"
The month with the highest snowfall is April (9.13").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Grass Range, MT
- Average snowfall days in September: 1 days
The month with the highest number of snowfall days is February (15.2 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Grass Range, MT
- Average daylight in September: 12h and 30min
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: 10h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 30min).
Average sunshine days in September
Grass Range, MT
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is September (19.3 days).
The month with the least sunshine days is April (8.3 days).
Average UV index in September
Grass Range, MT
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in September
Grass Range, MT
- Average cloud cover in September: 23
The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 16).
Average visibility in September
Grass Range, 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).
