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
Onset of December witnesses a reduction in the average high-temperature, falling from a fresh 50.2°F (10.1°C) in November to an icy 39.6°F (4.2°C). Throughout December, a steady low-temperature average of 28.6°F (-1.9°C) is noted.Humidity
The average relative humidity in December is 81%.Rainfall
In Riley, in December, during 9.4 rainfall days, 1.85" (47mm) of precipitation is typically accumulated. In Riley, during the entire year, the rain falls for 147.1 days and collects up to 25.87" (657mm) of precipitation.Snowfall
Months with snowfall in Riley, Indiana, are January through April, November and December. The month with the most snowfall in Riley is December, when snow falls for 4.8 days and typically aggregates up to 1.85" (47mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:50 am and sunset at 5:26 pm. On the last day of the month, sunrise is at 8:09 am and sunset at 5:35 pm EST.
Sunshine
The average sunshine in December in Riley, Indiana, is 4.4h.UV index
January, February, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 2 during December translates into the following directions:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Frequently asked questions
How cold is it in Riley in December?
What is the average humidity in December in Riley?
How much does it rain in Riley in December?
When does it snow the most in Riley?
How many days does it snow in December in Riley?
What is the month with the shortest days in Riley?
What is the average length of the day in December in Riley?
When is the sunrise / sunset in December in Riley?
How long on average sun shines in December in Riley?
What is the month with the lowest UV index in Riley?
What is the UV index reading in December in Riley?
Average temperature in December
Riley, IN
- Average high temperature in December: 39.6°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (34.3°F).
- Average low temperature in December: 28.6°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (22.1°F).
Average pressure in December
Riley, IN
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Riley, IN
- Average wind speed in December: 9.1mph
The windiest months (with the highest average wind speed) are January and February (9.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.9mph).
Average humidity in December
Riley, IN
- Average humidity in December: 81%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Riley, IN
- Average rainfall in December: 1.85"
The wettest month (with the highest rainfall) is April (3.62").
The driest month (with the least rainfall) is February (1.42").
Average rainfall days in December
Riley, IN
- Average rainfall days in December: 9.4 days
The month with the highest number of rainy days is May (19 days).
The month with the least rainy days is February (7.8 days).
Average snowfall in December
Riley, IN
- Average snowfall in December: 1.85"
The month with the highest snowfall is December (1.85").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Riley, IN
- Average snowfall days in December: 4.8 days
The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Riley, IN
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in December
Riley, IN
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (19 days).
The month with the least sunshine days is May (9.3 days).
Average UV index in December
Riley, IN
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in December
Riley, IN
- Average cloud cover in December: 54
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are June, August and September (Cloud cover 31).
Average visibility in December
Riley, IN
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Riley, Indiana, USA
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