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 transition into September is accompanied by a temperature decrease, with the average high-temperature shifting from a warm 77.2°F (25.1°C) in August to an enjoyable 65.8°F (18.8°C). Nightly readings in September display a noticeable downturn from daily highs, with the average low-temperature registering a cold 38.7°F (3.7°C).Humidity
The average relative humidity in September is 64%.Rainfall
In Yaak, in September, during 8.8 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. In Yaak, during the entire year, the rain falls for 136.3 days and collects up to 15.35" (390mm) 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 0.4 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
In September, the average length of the day 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, sunrise is at 7:42 am and sunset at 7:22 pm MDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
The average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: In September, a daily UV index of 3 turns into the following recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Yaak?
What is the average humidity in September?
How many days does it rain in September in Yaak?
When does it start to snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
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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