December weather forecast
Harper, IN

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Weather in December

December, the first month of the winter in Harper, is still a cold month, with an average temperature varying between 29.5°F (-1.4°C) and 40.6°F (4.8°C).

Temperature

As December begins, there is a decrease in the average high-temperature, falling from a cool 50.9°F (10.5°C) in November to an icy 40.6°F (4.8°C). In Harper, in December, the average low-temperature is a freezing cold 29.5°F (-1.4°C).

Humidity

With an average relative humidity of 82%, December is the most humid month.

Rainfall

In Harper, during December, the rain falls for 9.9 days and regularly aggregates up to 1.26" (32mm) of precipitation. In Harper, Indiana, during the entire year, the rain falls for 137.6 days and collects up to 17.99" (457mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In Harper, Indiana, in December, snow falls for 6.6 days, with typically accumulated 0.91" (23mm) of snow. Throughout the year, there are 29.3 snowfall days, and 5.35" (136mm) of snow is accumulated.

Daylight

With an average of 9h and 30min of daylight, December has the shortest days of the year.
On the first day of December in Harper, sunrise is at 7:43 am and sunset at 5:20 pm. On the last day of the month, sunrise is at 8:01 am and sunset at 5:29 pm EST.

Sunshine

In Harper, the average sunshine in December is 4.1h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the average person.
Note: The average daily UV index of 1 in December transforms into the following instructions:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Consider this! The reflection from snow can almost double the intensity of the Sun's UV radiation.
Updated: Aug 31, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

The average high-temperature, in December, in Harper, is 40.6°F (4.8°C), while the average low-temperature is 29.5°F (-1.4°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which factors the actual air temperature with the relative humidity, in August is appraised at 87.8°F (31°C).

What is the most humid month?

December is the most humid month, with an average relative humidity of 82%.

What is the average humidity in December?

In Harper, the average relative humidity in December is 82%.

How much does it rain in December?

In Harper, in December, during 9.9 rainfall days, 1.26" (32mm) of precipitation is typically accumulated.

How many days does it snow in December?

In December, it is snowing for 6.6 days. Throughout December, 0.91" (23mm) of snow is accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 30min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 28min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:43 am and sunset at 5:20 pm. On the last day of the month, sunrise is at 8:01 am and sunset at 5:29 pm EST.

How many hours of sunshine does Harper have in December?

In December, the average sunshine duration is 4.1h.

When is the lowest UV index?

The month with the lowest UV index is December, with an average maximum UV index of 1.

What is the UV index intensity in December?

The average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a low health risk from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Harper, IN

Average temperature in December - Harper, IN
  • Average high temperature in December: 40.6°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (34.9°F).

  • Average low temperature in December: 29.5°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 (22.8°F).

Average pressure in December
Harper, IN

Average pressure in December - Harper, IN
  • Average pressure in December: 30.12"Hg

The months with the highest atmospheric pressure are January and November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Harper, IN

Average wind speed in December - Harper, IN
  • Average wind speed in December: 8.5mph

The windiest months (with the highest average wind speed) are January and February (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.4mph).

Average humidity in December
Harper, IN

Average humidity in December - Harper, IN
  • Average humidity in December: 82%

The month with the highest relative humidity is December (82%).
The month with the lowest relative humidity is October (74%).

Average rainfall in December
Harper, IN

Average rainfall in December - Harper, IN
  • Average rainfall in December: 1.26"

The wettest month (with the highest rainfall) is May (2.01").
The driest month (with the least rainfall) is September (0.98").

Average rainfall days in December
Harper, IN

Average rainfall days in December - Harper, IN
  • Average rainfall days in December: 9.9 days

The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is February (7.9 days).

Average snowfall in December
Harper, IN

Average snowfall in December - Harper, IN
  • Average snowfall in December: 0.91"

The month with the highest snowfall is March (1.46").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Harper, IN

Average snowfall days in December - Harper, IN
  • Average snowfall days in December: 6.6 days

The month with the highest number of snowfall days is February (7.3 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
Harper, IN

Average daylight in December / Average sunshine in December - Harper, IN
  • Average daylight in December: 9h and 3min

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 30min).

  • Average sunshine in December: 4h and 1min

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 0min).

Average sunshine days in December
Harper, IN

Average sunshine days in December - Harper, IN
  • Average sunshine days in December: 16.2 days

The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (12.4 days).

Average UV index in December
Harper, IN

Average UV index in December - Harper, IN
  • Average UV index in December: 1

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
Harper, IN

Average cloud cover in December - Harper, IN
  • Average cloud cover in December: 56

The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in December
Harper, IN

Average visibility in December - Harper, IN
  • 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).

Harper, Indiana, USA

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