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 suggests a modest reduction in the average high-temperature, shifting from a moderately hot 81.3°F (27.4°C) in August to an agreeable 70.5°F (21.4°C). In Simpson, September nights witness a steady temperature drop to a fresh 52.5°F (11.4°C).Humidity
In September, the average relative humidity is 45%.Rainfall
In Simpson, Montana, in September, during 7.6 rainfall days, 0.63" (16mm) of precipitation is typically accumulated. Throughout the year, there are 98.7 rainfall days, and 8.23" (209mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows in Simpson. Throughout September, in the average 0.2 snowfall days, it receives 0.51" (13mm) of snow. In Simpson, during the entire year, snow falls for 53.5 days and aggregates up to 14.25" (362mm) of snow.Daylight
In Simpson, the average length of the day in September is 12h and 34min.On the first day of September in Simpson, sunrise is at 6:38 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:00 pm MDT.
Sunshine
In Simpson, the average sunshine in September is 10.1h.UV index
In Simpson, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: In September, an average UV index of 4 transforms into the following instructions:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Mind this! Nearly twice the UV radiation from the Sun can be reflected by the snow.
Frequently asked questions
What are September temperatures in Simpson?
What is the average humidity in September in Simpson?
How much does it rain in Simpson in September?
When does it start snowing in Simpson?
How many hours of daylight does Simpson have in September?
When are sunrise and sunset in September in Simpson?
How many hours of sunshine does Simpson have in September?
What is the UV index intensity in September in Simpson?
Average temperature in September
Simpson, MT
- Average high temperature in September: 70.5°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The months with the lowest average high temperature are January and December (27.1°F).
- Average low temperature in September: 52.5°F
The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is February (13.5°F).
Average pressure in September
Simpson, MT
- Average pressure in September: 29.93"Hg
The months with the highest atmospheric pressure are January and February (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Simpson, MT
- Average wind speed in September: 9mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (8.5mph).
Average humidity in September
Simpson, MT
- Average humidity in September: 45%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is August (40%).
Average rainfall in September
Simpson, MT
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is June (1.5").
The driest month (with the least rainfall) is December (0.31").
Average rainfall days in September
Simpson, MT
- Average rainfall days in September: 7.6 days
The month with the highest number of rainy days is May (13.8 days).
The month with the least rainy days is February (4 days).
Average snowfall in September
Simpson, MT
- Average snowfall in September: 0.51"
The month with the highest snowfall is February (2.72").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Simpson, MT
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is February (11 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Simpson, MT
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 18min).
- Average sunshine in September: 10h and 1min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is February (Average sunshine: 5h and 18min).
Average sunshine days in September
Simpson, MT
- Average sunshine days in September: 20.3 days
The month with the most sunshine days is September (20.3 days).
The month with the least sunshine days is April (12.8 days).
Average UV index in September
Simpson, 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, October, November and December (UV index 2).
Average cloud cover in September
Simpson, MT
- Average cloud cover in September: 22
The month with the most cloud cover is February (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 16).
Average visibility in September
Simpson, 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).
Simpson, Montana, USA
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