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 onset of September results in a decrease in the average high-temperature, receding from a moderately hot 77.2°F (25.1°C) in August to an enjoyable 65.8°F (18.8°C). Yaak, after hot September days, encounters a marked drop to an average nighttime temperature of 38.7°F (3.7°C).Humidity
The average relative humidity in September is 64%.Rainfall
In Yaak, in September, it is raining for 8.8 days, with typically 0.79" (20mm) of accumulated precipitation. Throughout the year, there are 136.3 rainfall days, and 15.35" (390mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall in Yaak, Montana. September is the first month it typically snows in Yaak, Montana. Throughout September, in the average 0.4 snowfall days, it receives 0.28" (7mm) of snow. In Yaak, during the entire year, snow falls for 110.7 days and aggregates up to 46.81" (1189mm) of snow.Daylight
The average length of the day in September is 12h and 34min.On the first day of the month, sunrise is at 7:00 am and sunset at 8:24 pm. On the last day of September, in Yaak, sunrise is at 7:42 am and sunset at 7:22 pm MDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In Yaak, the average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 3 in September translates into these instructions:
Act with care - The need to guard against sun damage is communicated. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
Frequently asked questions
What is the temperature in September in Yaak?
What is the average humidity in September in Yaak?
How much does it rain in Yaak in September?
When does it start to snow in Yaak?
What is the average length of the day in September in Yaak?
When are sunrise and sunset in September in Yaak?
How many hours of sunshine does Yaak have in September?
What is the UV index intensity in September in Yaak?
Average temperature in September
Yaak, MT
- Average high temperature in September: 65.8°F
The warmest month (with the highest average high temperature) is July (77.4°F).
The month with the lowest average high temperature is December (25.5°F).
- Average low temperature in September: 38.7°F
The month with the highest average low temperature is August (45.1°F).
The coldest month (with the lowest average low temperature) is December (13.1°F).
Average pressure in September
Yaak, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Yaak, MT
- Average wind speed in September: 3.8mph
The windiest month (with the highest average wind speed) is June (4.4mph).
The calmest month (with the lowest average wind speed) is December (3.4mph).
Average humidity in September
Yaak, MT
- Average humidity in September: 64%
The month with the highest relative humidity is January (95%).
The month with the lowest relative humidity is August (55%).
Average rainfall in September
Yaak, MT
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is March (1.85").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days in September
Yaak, MT
- Average rainfall days in September: 8.8 days
The month with the highest number of rainy days is April (17 days).
The month with the least rainy days is August (6.1 days).
Average snowfall in September
Yaak, MT
- Average snowfall in September: 0.28"
The month with the highest snowfall is February (10").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Yaak, MT
- Average snowfall days in September: 0.4 days
The month with the highest number of snowfall days is December (22.1 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Yaak, 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: 9h and 1min
The month with the most sunshine is August (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 6min).
Average sunshine days in September
Yaak, MT
- Average sunshine days in September: 18.4 days
The month with the most sunshine days is August (21.6 days).
The month with the least sunshine days is March (6.3 days).
Average UV index in September
Yaak, MT
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Yaak, MT
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility in September
Yaak, MT
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August and September (6mi).
The month with the lowest visibility is January (2mi).
Yaak, Montana, USA
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