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
Transition from August to September is accompanied by a temperature drop, with average high-temperatures decreasing from a warm 76.8°F (24.9°C) to a refreshing 65.5°F (18.6°C). A noticeable downturn in temperature characterizes the September nights, averaging at an icy 39.2°F (4°C).Humidity
In Happy Haven, the average relative humidity in September is 64%.Rainfall
In Happy Haven, during September, the rain falls for 8.5 days and regularly aggregates up to 0.71" (18mm) of precipitation. Throughout the year, there are 126.4 rainfall days, and 11.22" (285mm) of precipitation is accumulated.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 0.04" (1mm) of snow. Throughout the year, there are 97 snowfall days, and 33.86" (860mm) of snow is accumulated.Daylight
In Happy Haven, the average length of the day in September is 12h and 34min.On the first day of the month, sunrise is at 6:55 am and sunset at 8:18 pm. On the last day of September, sunrise is at 7:36 am and sunset at 7:17 pm MDT.
Sunshine
In Happy Haven, the average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The daily high UV index of 3 during September translates into the following recommendations:
Ensure safety - Recommendations to avert sunburn are presented. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Forewarned is forearmed! The Sun's UV radiation can be almost doubled in intensity by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Happy Haven in September?
What is the average humidity in September?
How many days does it rain in September?
When does it start snowing?
How many hours of daylight does Happy Haven have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Happy Haven have in September?
How high is the UV index in September?
Average temperature in September
Happy Haven, MT
- Average high temperature in September: 65.5°F
The warmest month (with the highest average high temperature) is July (77.9°F).
The month with the lowest average high temperature is December (25.7°F).
- Average low temperature in September: 39.2°F
The month with the highest average low temperature is August (45.5°F).
The coldest month (with the lowest average low temperature) is February (13.5°F).
Average pressure in September
Happy Haven, MT
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Happy Haven, MT
- Average wind speed in September: 3.8mph
The windiest month (with the highest average wind speed) is April (4.6mph).
The calmest months (with the lowest average wind speed) are August and December (3.7mph).
Average humidity in September
Happy Haven, MT
- Average humidity in September: 64%
The month with the highest relative humidity is January (93%).
The month with the lowest relative humidity is August (55%).
Average rainfall in September
Happy Haven, MT
- Average rainfall in September: 0.71"
The wettest month (with the highest rainfall) is June (1.42").
The driest month (with the least rainfall) is August (0.43").
Average rainfall days in September
Happy Haven, MT
- Average rainfall days in September: 8.5 days
The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is August (6.3 days).
Average snowfall in September
Happy Haven, MT
- Average snowfall in September: 0.04"
The month with the highest snowfall is January (7.72").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Happy Haven, MT
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is December (19.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Happy Haven, MT
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Happy Haven, MT
- Average sunshine days in September: 19 days
The month with the most sunshine days is July (21.5 days).
The month with the least sunshine days is March (7.7 days).
Average UV index in September
Happy Haven, 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
Happy Haven, MT
- Average cloud cover in September: 24
The month with the most cloud cover is January (Cloud cover 65).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in September
Happy Haven, MT
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The month with the lowest visibility is January (3mi).
Happy Haven, Montana, USA
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