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
With the arrival of December, Johnston notices a mild change in the average high-temperature, sliding from November's comfortable 61.9°F (16.6°C) to a mild 56.1°F (13.4°C). The average low-temperature of 41.4°F (5.2°C) is witnessed during December.Humidity
The most humid month is December, with an average relative humidity of 76%.Rainfall
December is the month with the most rainfall. Rain falls for 11.2 days and accumulates 3.03" (77mm) of precipitation.Snowfall
January through March and December are months with snowfall in Johnston, South Carolina. December is the first month it typically snows. Throughout December, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 1.2 snowfall days, and 1.02" (26mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 54min of daylight.On the first day of the month, sunrise is at 7:14 am and sunset at 5:18 pm. On the last day of December, sunrise is at 7:32 am and sunset at 5:29 pm EST.
Sunshine
The month with the least sunshine is December, with an average of 5.4h of sunshine.UV index
In December, the average daily maximum UV index is 3. A UV Index of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: An average UV index of 3 in December transforms into this advice:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average December temperature in Johnston?
What is the most humid month?
What is the average humidity in December?
What is the wettest month?
How many days 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 Johnston have in December?
How high is the UV index in December?
Average temperature in December
Johnston, SC
- Average high temperature in December: 56.1°F
The warmest month (with the highest average high temperature) is July (91.4°F).
The month with the lowest average high temperature is January (52.7°F).
- Average low temperature in December: 41.4°F
The month with the highest average low temperature is July (72.5°F).
The coldest month (with the lowest average low temperature) is January (36.9°F).
Average pressure in December
Johnston, SC
- Average pressure in December: 30.14"Hg
The months with the highest atmospheric pressure are January, November and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in December
Johnston, SC
- Average wind speed in December: 7.5mph
The windiest months (with the highest average wind speed) are February and April (8.1mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in December
Johnston, SC
- Average humidity in December: 76%
The month with the highest relative humidity is December (76%).
The month with the lowest relative humidity is July (70%).
Average rainfall in December
Johnston, SC
- Average rainfall in December: 3.03"
The wettest month (with the highest rainfall) is December (3.03").
The driest month (with the least rainfall) is September (1.42").
Average rainfall days in December
Johnston, SC
- Average rainfall days in December: 11.2 days
The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is November (7.8 days).
Average snowfall in December
Johnston, SC
- Average snowfall in December: 0.04"
The month with the highest snowfall is February (0.59").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in December
Johnston, SC
- Average snowfall days in December: 0.1 days
The months with the highest number of snowfall days are January and February (0.4 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Johnston, 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 months with the most sunshine are June and July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 24min).
Average sunshine days in December
Johnston, SC
- Average sunshine days in December: 18.6 days
The month with the most sunshine days is October (21.8 days).
The month with the least sunshine days is July (11.2 days).
Average UV index in December
Johnston, SC
- Average UV index in December: 3
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 2).
Average cloud cover in December
Johnston, SC
- Average cloud cover in December: 41
The month with the most cloud cover is December (Cloud cover 41).
The month with the least cloud cover is October (Cloud cover 27).
Average visibility in December
Johnston, SC
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Johnston, South Carolina, USA
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