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 a warm 81.1°F (27.3°C) in August to a pleasant 70°F (21.1°C). September witnesses an average low-temperature hovering around a fresh 52°F (11.1°C).Humidity
The average relative humidity in September is 47%.Rainfall
In Harlem, in September, during 7.1 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. In Harlem, during the entire year, the rain falls for 99.1 days and collects up to 10.12" (257mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.71" (18mm) of snow. In Harlem, during the entire year, snow falls for 57.6 days and aggregates up to 21.69" (551mm) of snow.Daylight
The average length of the day in September is 12h and 34min.On the first day of September, sunrise is at 6:33 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 6:55 pm MDT.
Sunshine
In Harlem, the average sunshine in September is 10.2h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: During September, 4 as the daily maximum UV index converts into the following advice:
Heed the precautions - Suggestions to avoid sunburn are made. Around midday, solar radiation is most harmful; hence, exposure should be limited. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When does it start to snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Harlem have in September?
What is the UV index intensity in September?
Average temperature in September
Harlem, MT
- Average high temperature in September: 70°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is February (26.2°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is August (60.3°F).
The coldest month (with the lowest average low temperature) is February (12.6°F).
Average pressure in September
Harlem, MT
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is February (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.83"Hg).
Average wind speed in September
Harlem, MT
- Average wind speed in September: 9.1mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (8.7mph).
Average humidity in September
Harlem, MT
- Average humidity in September: 47%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is August (42%).
Average rainfall in September
Harlem, MT
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is June (1.85").
The driest months (with the least rainfall) are February, March and December (0.55").
Average rainfall days in September
Harlem, MT
- Average rainfall days in September: 7.1 days
The month with the highest number of rainy days is May (13.2 days).
The month with the least rainy days is February (4.6 days).
Average snowfall in September
Harlem, MT
- Average snowfall in September: 0.71"
The month with the highest snowfall is January (4.02").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Harlem, MT
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is January (12.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Harlem, 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 24min).
- 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 12min).
Average sunshine days in September
Harlem, MT
- Average sunshine days in September: 21 days
The month with the most sunshine days is July (21.6 days).
The month with the least sunshine days is April (12.5 days).
Average UV index in September
Harlem, MT
- Average UV index in September: 4
The months with the highest UV index are June and 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
Harlem, 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 15).
Average visibility in September
Harlem, 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).
Harlem, Montana, USA
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