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 shift from August to September involves a decrease in the average high-temperature, from a moderately hot 77.9°F (25.5°C) to an agreeable 68.9°F (20.5°C). During the nights in September, an average low-temperature of 47.7°F (8.7°C) is observed.Humidity
In September, the average relative humidity is 40%.Rainfall
In September, in Opal, the rain falls for 8.6 days. Throughout September, 0.83" (21mm) of precipitation is accumulated. Throughout the year, in Opal, Wyoming, there are 96.8 rainfall days, and 11.46" (291mm) of precipitation is accumulated.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows in Opal, Wyoming. Throughout September, in the average 0.7 snowfall days, it receives 0.35" (9mm) of snow. Throughout the year, there are 88.9 snowfall days, and 38.86" (987mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 28min.On the first day of September in Opal, sunrise is at 6:48 am and sunset at 7:54 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 7:04 pm MDT.
Sunshine
The average sunshine in September in Opal is 10.5h.UV index
In September, the average daily maximum UV index in Opal, Wyoming, is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, an average UV index of 4 transforms into the following instructions:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Opal?
What is the average humidity in September in Opal?
How much does it rain in Opal in September?
When does it start snowing in Opal?
How many hours of daylight does Opal have in September?
When are sunrise and sunset in September in Opal?
How many hours of sunshine does Opal have in September?
What is the UV index intensity in September in Opal?
Average temperature in September
Opal, WY
- Average high temperature in September: 68.9°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is December (25.7°F).
- Average low temperature in September: 47.7°F
The month with the highest average low temperature is July (55°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in September
Opal, WY
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Opal, WY
- Average wind speed in September: 8.3mph
The windiest month (with the highest average wind speed) is April (9.8mph).
The calmest month (with the lowest average wind speed) is July (7.5mph).
Average humidity in September
Opal, WY
- Average humidity in September: 40%
The months with the highest relative humidity are January and February (87%).
The month with the lowest relative humidity is August (35%).
Average rainfall in September
Opal, WY
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is May (2.01").
The driest month (with the least rainfall) is August (0.59").
Average rainfall days in September
Opal, WY
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is May (13.3 days).
The month with the least rainy days is February (5 days).
Average snowfall in September
Opal, WY
- Average snowfall in September: 0.35"
The month with the highest snowfall is March (6.81").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Opal, WY
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is February (15.3 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Opal, WY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 10h and 3min
The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 5h and 42min).
Average sunshine days in September
Opal, WY
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is October (19.4 days).
The month with the least sunshine days is April (9.7 days).
Average UV index in September
Opal, WY
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in September
Opal, WY
- Average cloud cover in September: 14
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 12).
Average visibility in September
Opal, WY
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).
Opal, Wyoming, USA
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