December weather forecastPostville, IA
December
Weather in December
December, the first month of the winter in Postville, is still a freezing cold month, with an average temperature ranging between max 28.9°F (-1.7°C) and min 18.7°F (-7.4°C).Temperature
December comes with a decrease in the average high-temperature, falling from a wintry 42.6°F (5.9°C) in November to a freezing cold 28.9°F (-1.7°C). In Postville, December nights witness a steady temperature drop to a still subzero cold 18.7°F (-7.4°C).Humidity
In Postville, the average relative humidity in December is 85%.Rainfall
In December, the rain falls for 5.4 days. Throughout December, 1.42" (36mm) of precipitation is accumulated. In Postville, Iowa, during the entire year, the rain falls for 131 days and collects up to 27.91" (709mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Postville, in December, during 11.9 snowfall days, 4.06" (103mm) of snow is typically accumulated. In Postville, during the entire year, snow falls for 52.3 days and aggregates up to 21.26" (540mm) of snow.Daylight
The month with the shortest days in Postville is December, with an average of 9h and 6min of daylight.On the first day of December, sunrise is at 7:18 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:37 am and sunset at 4:41 pm CST.
Sunshine
In December, the average sunshine is 4h.UV index
January, November and December, with an average maximum UV index of 1, are months with the lowest UV index in Postville. A UV Index estimate of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The daily high UV index of 1 during December translates into the following recommendations:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Postville, IA
- Average high temperature in December: 28.9°F
The warmest month (with the highest average high temperature) is July (79°F).
The month with the lowest average high temperature is January (22.5°F).
- Average low temperature in December: 18.7°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in December
Postville, IA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in December
Postville, IA
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in December
Postville, IA
- Average humidity in December: 85%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (75%).
Average rainfall in December
Postville, IA
- Average rainfall in December: 1.42"
The wettest month (with the highest rainfall) is June (4.33").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in December
Postville, IA
- Average rainfall days in December: 5.4 days
The month with the highest number of rainy days is June (17.7 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in December
Postville, IA
- Average snowfall in December: 4.06"
The month with the highest snowfall is February (5.16").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Postville, IA
- Average snowfall days in December: 11.9 days
The month with the highest number of snowfall days is January (13.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Postville, IA
- Average daylight in December: 9h and 6min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 4h and 0min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in December
Postville, IA
- Average sunshine days in December: 16.8 days
The month with the most sunshine days is September (17 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in December
Postville, IA
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in December
Postville, IA
- Average cloud cover in December: 60
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in December
Postville, IA
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
