December weather forecastDiagonal, IA
December
Weather in December
The first month of the winter, December, is also an icy month in Diagonal, Iowa, with an average temperature ranging between max 35.2°F (1.8°C) and min 23.2°F (-4.9°C).Temperature
The onset of December results in a decrease in the average high-temperature, receding from a frosty 48.4°F (9.1°C) in November to a cold 35.2°F (1.8°C). In the month of December, Diagonal witnesses a consistent average low-temperature of 23.2°F (-4.9°C).Humidity
In December, the average relative humidity in Diagonal, Iowa, is 78%.Rainfall
February and December are months with the least rain when the rain falls for 5.4 days and typically aggregates up to 0.71" (18mm) of rain.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 5.8 days. Throughout December, 1.42" (36mm) of snow is accumulated. Throughout the year, there are 28.7 snowfall days, and 11.85" (301mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:22 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:41 am and sunset at 4:59 pm CST.
Sunshine
In December, the average sunshine is 5h.UV index
In December, the average daily maximum UV index in Diagonal is 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.Note: In December, the UV index of 2 transforms into the following advice:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Diagonal, IA
- Average high temperature in December: 35.2°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: 23.2°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
Diagonal, IA
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Diagonal, IA
- Average wind speed in December: 9.9mph
The windiest months (with the highest average wind speed) are January, February and March (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in December
Diagonal, IA
- Average humidity in December: 78%
The month with the highest relative humidity is June (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Diagonal, IA
- Average rainfall in December: 0.71"
The wettest month (with the highest rainfall) is June (3.86").
The driest months (with the least rainfall) are February and December (0.71").
Average rainfall days in December
Diagonal, IA
- Average rainfall days in December: 5.4 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in December
Diagonal, IA
- Average snowfall in December: 1.42"
The month with the highest snowfall is January (3.54").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Diagonal, IA
- Average snowfall days in December: 5.8 days
The month with the highest number of snowfall days is January (8.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Diagonal, IA
- Average daylight in December: 9h and 18min
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: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in December
Diagonal, IA
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is November (21.2 days).
The month with the least sunshine days is May (10.6 days).
Average UV index in December
Diagonal, 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
Diagonal, IA
- Average cloud cover in December: 46
The month with the most cloud cover is January (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in December
Diagonal, IA
- 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).





