Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The onset of December aligns with a soft reduction in the average high-temperature, gently falling from a comfortable 61.7°F (16.5°C) in November to a cool 54.5°F (12.5°C). Iris's nights in December experience an average temperature drop to a wintry 39.7°F (4.3°C).Humidity
December is the most humid month, with an average relative humidity of 77%.Rainfall
The month with the most rainfall is December, when the rain falls for 12.3 days and typically aggregates up to 3.74" (95mm) of precipitation.Snowfall
January through March and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 0.3 snowfall days, it receives 0.12" (3mm) of snow. In Iris, during the entire year, snow falls for 2 days and aggregates up to 1.81" (46mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 54min of daylight.On the first day of the month, sunrise is at 7:18 am and sunset at 5:19 pm. On the last day of December, sunrise is at 7:35 am and sunset at 5:30 pm EST.
Sunshine
With an average of 5.3h of sunshine, December has the least sunshine of the year.UV index
In December, the average daily maximum UV index is 3. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: In December, the UV index of 3 transforms into the following advice:
Take necessary precautions - Defending against sun damage is advocated. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in December?
What is the most humid month?
What is the average humidity in December?
What is the rainiest month?
How much does it rain in December?
When does it start snowing?
What is the month with the shortest days?
What is the average length of the day in December?
When are sunrise and sunset in December?
What is the month with the least sunshine?
How many hours of sunshine does Iris have in December?
What is the UV index intensity in December?
Average temperature in December
Iris, SC
- Average high temperature in December: 54.5°F
The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is January (51.6°F).
- Average low temperature in December: 39.7°F
The month with the highest average low temperature is July (70.7°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).
Average pressure in December
Iris, SC
- Average pressure in December: 30.14"Hg
The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in December
Iris, SC
- Average wind speed in December: 6.8mph
The windiest month (with the highest average wind speed) is February (7.3mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in December
Iris, SC
- Average humidity in December: 77%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is July (70%).
Average rainfall in December
Iris, SC
- Average rainfall in December: 3.74"
The wettest month (with the highest rainfall) is December (3.74").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in December
Iris, SC
- Average rainfall days in December: 12.3 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is October (9.1 days).
Average snowfall in December
Iris, SC
- Average snowfall in December: 0.12"
The month with the highest snowfall is February (0.94").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in December
Iris, SC
- Average snowfall days in December: 0.3 days
The month with the highest number of snowfall days is January (0.8 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average daylight in December /
Average sunshine in December
Iris, SC
- Average daylight in December: 9h and 5min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in December: 5h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in December
Iris, SC
- Average sunshine days in December: 16.8 days
The month with the most sunshine days is October (20.8 days).
The month with the least sunshine days is July (10.3 days).
Average UV index in December
Iris, SC
- Average UV index in December: 3
The months with the highest UV index are June and August (UV index 7).
The month with the lowest UV index is January (UV index 2).
Average cloud cover in December
Iris, SC
- Average cloud cover in December: 42
The months with the most cloud cover are February and December (Cloud cover 42).
The months with the least cloud cover are June and October (Cloud cover 29).
Average visibility in December
Iris, SC
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Iris, South Carolina, USA
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