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
December brings a slight decrease in temperature, down from a comfortable 61.9°F (16.6°C) in November to a still refreshing 56.1°F (13.4°C). Throughout December, an average low-temperature of 41.4°F (5.2°C) is expected in Johnston.Humidity
December is the most humid month in Johnston, with an average relative humidity of 76%.Rainfall
December is the month with the most rainfall in Johnston. Rain falls for 11.2 days and accumulates 3.03" (77mm) of precipitation.Snowfall
Months with snowfall are January through March and December. December is the first month it typically snows in Johnston. Throughout December, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Johnston, during the entire year, snow falls for 1.2 days and aggregates up to 1.02" (26mm) of snow.Daylight
With an average of 9h and 54min of daylight, December has the shortest days of the year in Johnston.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
December has the least sunshine of the year in Johnston, with an average of 5.4h of sunshine.UV index
In Johnston, the average daily maximum UV index in December is 3. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index of 3 during December leads to these instructions:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Opt for tightly woven and loose clothing to enhance protection from the Sun. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Frequently asked questions
What is the temperature in December in Johnston?
What is the most humid month in Johnston?
What is the average humidity in December in Johnston?
What is the rainiest month in Johnston?
How many days does it rain in December in Johnston?
When does it start to snow in Johnston?
What is the month with the shortest days in Johnston?
How many hours of daylight does Johnston have in December?
When is the sunrise / sunset in December in Johnston?
What is the month with the least sunshine in Johnston?
How many hours of sunshine does Johnston have in December?
How high is the UV index in December in Johnston?
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
Weather forecast for your location
2. Allow the app to use your location
