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
In Merrimac, the average high-temperature in December decreases from a chilly 48°F (8.9°C) in November to a cold 36°F (2.2°C). Merrimac observes an average nighttime temperature of 24.6°F (-4.1°C) during December.Humidity
In Merrimac, the average relative humidity in December is 80%.Rainfall
February and December are months with the least rain in Merrimac when the rain falls for 7.3 days and typically aggregates up to 1.38" (35mm) of rain.Snowfall
January through April, October through December are months with snowfall. In December, it is snowing for 6 days. Throughout December, 1.65" (42mm) of snow is accumulated. In Merrimac, during the entire year, snow falls for 30.7 days and aggregates up to 15" (381mm) of snow.Daylight
The month with the shortest days in Merrimac is December, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:13 am and sunset at 4:39 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 4:48 pm CST.
Sunshine
In Merrimac, the average sunshine in December is 4.5h.UV index
In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for average individuals.Note: An average maximum UV index of 2 in December leads to these recommendations:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Be vigilant! The reflective nature of snow can increase the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
What is the driest month?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Merrimac have in December?
What is the UV index reading in December?
Average temperature in December
Merrimac, IA
- Average high temperature in December: 36°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in December: 24.6°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in December
Merrimac, IA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in December
Merrimac, IA
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).
Average humidity in December
Merrimac, IA
- Average humidity in December: 80%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Merrimac, IA
- Average rainfall in December: 1.38"
The wettest month (with the highest rainfall) is May (4.29").
The driest months (with the least rainfall) are February and December (1.38").
Average rainfall days in December
Merrimac, IA
- Average rainfall days in December: 7.3 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.6 days).
Average snowfall in December
Merrimac, IA
- Average snowfall in December: 1.65"
The month with the highest snowfall is January (4.76").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Merrimac, IA
- Average snowfall days in December: 6 days
The month with the highest number of snowfall days is January (9.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Merrimac, IA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 4h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in December
Merrimac, IA
- Average sunshine days in December: 18 days
The month with the most sunshine days is October (18.4 days).
The month with the least sunshine days is May (10.6 days).
Average UV index in December
Merrimac, IA
- 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
Merrimac, IA
- Average cloud cover in December: 53
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are July, August and September (Cloud cover 31).
Average visibility in December
Merrimac, IA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Merrimac, Iowa, USA
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