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 into September subtly marks a drop in the average high-temperature, moderately moving from a moderately hot 76.6°F (24.8°C) in August to an agreeable 68.5°F (20.3°C). Lyman throughout September, records an average low-temperature of 47.8°F (8.8°C).Humidity
The average relative humidity in September is 39%.Rainfall
In Lyman, in September, during 8 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. Throughout the year, there are 112.2 rainfall days, and 11.57" (294mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.7 snowfall days, it receives 0.43" (11mm) of snow. Throughout the year, there are 85.7 snowfall days, and 41.18" (1046mm) of snow is accumulated.Daylight
In Lyman, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:48 am and sunset at 7:53 pm. On the last day of September, sunrise is at 7:17 am and sunset at 7:04 pm MDT.
Sunshine
The average sunshine in September is 10.5h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: In September, a daily UV index of 4 turns into the following recommendations:
Guard yourself - Precautionary measures against sun damage are advocated. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Take heed! The reflection of snow can intensify 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 average September temperature?
What is the average humidity in September?
How many days does it rain in September in Lyman?
When does it start snowing?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Lyman have in September?
What is the UV index intensity in September?
Average temperature in September
Lyman, WY
- Average high temperature in September: 68.5°F
The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is December (26.6°F).
- Average low temperature in September: 47.8°F
The month with the highest average low temperature is July (55.6°F).
The coldest month (with the lowest average low temperature) is January (12.2°F).
Average pressure in September
Lyman, WY
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.28"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Lyman, WY
- Average wind speed in September: 8.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is July (7.6mph).
Average humidity in September
Lyman, WY
- Average humidity in September: 39%
The months with the highest relative humidity are January and February (82%).
The months with the lowest relative humidity are July and August (36%).
Average rainfall in September
Lyman, WY
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is May (2.01").
The driest months (with the least rainfall) are January and July (0.63").
Average rainfall days in September
Lyman, WY
- Average rainfall days in September: 8 days
The month with the highest number of rainy days is May (16.1 days).
The month with the least rainy days is November (6 days).
Average snowfall in September
Lyman, WY
- Average snowfall in September: 0.43"
The month with the highest snowfall is March (8.78").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Lyman, WY
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is March (15.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Lyman, WY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 10h and 3min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in September
Lyman, WY
- Average sunshine days in September: 18.8 days
The month with the most sunshine days is October (19.2 days).
The month with the least sunshine days is April (9.4 days).
Average UV index in September
Lyman, WY
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in September
Lyman, WY
- Average cloud cover in September: 13
The month with the most cloud cover is February (Cloud cover 36).
The month with the least cloud cover is August (Cloud cover 12).
Average visibility in September
Lyman, WY
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
Lyman, Wyoming, USA
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