December weather forecastMercer, MO
December
Weather in December
The first month of the winter, December, is also a wintry month in Mercer, Missouri, with temperature in the range of an average low of 23.4°F (-4.8°C) and an average high of 35.6°F (2°C).Temperature
Stepping into December, Mercer observes a temperature decline, with the average high falling from November's frosty 48.6°F (9.2°C) to an icy 35.6°F (2°C). December generally records an average low-temperature of 23.4°F (-4.8°C).Humidity
In Mercer, Missouri, the average relative humidity in December is 79%.Rainfall
The months with the least rainfall are January and December Rain falls for 5.7 days and accumulates 0.67" (17mm) of rain.Snowfall
Months with snowfall are January through May, October through December. In Mercer, during December, snow falls for 5.9 days and regularly aggregates up to 1.14" (29mm) of snow. Throughout the year, there are 30.2 snowfall days, and 10.16" (258mm) of snow is accumulated.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:18 am and sunset at 4:47 pm. On the last day of December, sunrise is at 7:37 am and sunset at 4:57 pm CST.
Sunshine
The average sunshine in December is 4.9h.UV index
In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In December, an average UV index of 2 transforms into the following instructions:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mercer, MO
- Average high temperature in December: 35.6°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in December: 23.4°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).
Average pressure in December
Mercer, MO
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in December
Mercer, MO
- Average wind speed in December: 9.9mph
The windiest months (with the highest average wind speed) are January, February and March (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).
Average humidity in December
Mercer, MO
- Average humidity in December: 79%
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Mercer, MO
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is June (3.43").
The driest months (with the least rainfall) are January and December (0.67").
Average rainfall days in December
Mercer, MO
- Average rainfall days in December: 5.7 days
The month with the highest number of rainy days is June (17.3 days).
The month with the least rainy days is January (4.8 days).
Average snowfall in December
Mercer, MO
- Average snowfall in December: 1.14"
The month with the highest snowfall is January (2.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Mercer, MO
- Average snowfall days in December: 5.9 days
The month with the highest number of snowfall days is January (8.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mercer, MO
- Average daylight in December: 9h and 18min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 4h and 54min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Mercer, MO
- Average sunshine days in December: 20.3 days
The month with the most sunshine days is December (20.3 days).
The month with the least sunshine days is June (8.9 days).
Average UV index in December
Mercer, MO
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Mercer, MO
- Average cloud cover in December: 47
The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in December
Mercer, MO
- 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).





