December weather forecast
Lebanon, OR

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Weather in December

December, the final month of the year, brings with it the coldest temperatures and the highest rainfall averages. The weather in December witnesses a significant increase in precipitation, leading to the peak monthly rainfall average of 4.41" (112mm). Temperatures drop to their annual lows, and the wind speed slightly picks up compared to the previous months, adding to the chill factor. With limited daylight and primarily overcast skies, December sets in the winter mood. Thus, the year concludes with a strikingly cold and wet month.

Temperature

December is the coldest month of the year, registering average temperatures as high as 45.3°F (7.4°C) and as low as 34.2°F (1.2°C).

Humidity

The months with the highest humidity are January through March and December, with an average relative humidity of 86%.

Rainfall

December is the month with the most rainfall in Lebanon. Rain falls for 18 days and accumulates 4.41" (112mm) of precipitation.

Snowfall

Months with snowfall in Lebanon are January through March, November and December. In Lebanon, in December, during 0.7 snowfall days, 0.31" (8mm) of snow is typically accumulated. Throughout the year, there are 5.6 snowfall days, and 4.09" (104mm) of snow is accumulated.

Daylight

With an average of 8h and 54min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:28 am and sunset at 4:33 pm. On the last day of December, sunrise is at 7:48 am and sunset at 4:41 pm PST.

Sunshine

The average sunshine in December is 4.3h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: A maximum UV index of 2 in December translates into the following recommendations:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Updated: Aug 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months?

The coldest month is December, with an average high-temperature of 45.3°F (7.4°C) and an average low-temperature of 34.2°F (1.2°C).

What are the temperatures in December?

The average high-temperature, in December, in Lebanon, is 45.3°F (7.4°C), while the average low-temperature is 34.2°F (1.2°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which represents the influence of relative humidity on air temperature, in August is estimated at 84.2°F (29°C).

What is the most humid month?

January through March and December, with an average relative humidity of 86%, are most humid months.

What is the average humidity in December?

In Lebanon, the average relative humidity in December is 86%.

What is the rainiest month?

December is the month with the most rainfall in Lebanon. Rain falls for 18 days and accumulates 4.41" (112mm) of precipitation.

How many days does it rain in December?

In Lebanon, in December, during 18 rainfall days, 4.41" (112mm) of precipitation is typically accumulated.

How much does it snow in December?

In Lebanon, during December, snow falls for 0.7 days and regularly aggregates up to 0.31" (8mm) of snow.

What is the month with the shortest days?

With an average of 8h and 54min of daylight, December has the shortest days of the year in Lebanon.

How many hours of daylight does Lebanon have in December?

In December, the average day length is 8h and 53min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:28 am and sunset at 4:33 pm. On the last day of the month, sunrise is at 7:48 am and sunset at 4:41 pm PST.

How long on average sun shines in December?

The average sunshine duration in December is 4.3h.

When is the lowest UV index?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

How high is the UV index in December?

The average daily maximum UV index in December in Lebanon is 2. A UV Index reading of 2, and below, represents a minimal hazard to health from unsafe exposure to Sun's UV rays.
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
Lebanon, OR

Average temperature in December - Lebanon, OR
  • Average high temperature in December: 45.3°F

The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (45.3°F).

  • Average low temperature in December: 34.2°F

The month with the highest average low temperature is August (51.8°F).
The coldest month (with the lowest average low temperature) is December (34.2°F).

Average pressure in December
Lebanon, OR

Average pressure in December - Lebanon, OR
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).

Average wind speed in December
Lebanon, OR

Average wind speed in December - Lebanon, OR
  • Average wind speed in December: 5mph

The windiest months (with the highest average wind speed) are January and March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).

Average humidity in December
Lebanon, OR

Average humidity in December - Lebanon, OR
  • Average humidity in December: 86%

The months with the highest relative humidity are January, February, March and December (86%).
The month with the lowest relative humidity is August (66%).

Average rainfall in December
Lebanon, OR

Average rainfall in December - Lebanon, OR
  • Average rainfall in December: 4.41"

The wettest month (with the highest rainfall) is December (4.41").
The driest month (with the least rainfall) is July (0.24").

Average rainfall days in December
Lebanon, OR

Average rainfall days in December - Lebanon, OR
  • Average rainfall days in December: 18 days

The month with the highest number of rainy days is March (20.1 days).
The months with the least rainy days are July and August (3.8 days).

Average snowfall in December
Lebanon, OR

Average snowfall in December - Lebanon, OR
  • Average snowfall in December: 0.31"

The month with the highest snowfall is February (2.13").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Lebanon, OR

Average snowfall days in December - Lebanon, OR
  • Average snowfall days in December: 0.7 days

The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Lebanon, OR

Average daylight in December / Average sunshine in December - Lebanon, OR
  • Average daylight in December: 8h and 5min

The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in December: 4h and 2min

The month with the most sunshine is August (Average sunshine: 11h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).

Average sunshine days in December
Lebanon, OR

Average sunshine days in December - Lebanon, OR
  • Average sunshine days in December: 11.6 days

The month with the most sunshine days is July (25.6 days).
The month with the least sunshine days is March (9.1 days).

Average UV index in December
Lebanon, OR

Average UV index in December - Lebanon, OR
  • Average UV index in December: 2

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December
Lebanon, OR

Average cloud cover in December - Lebanon, OR
  • Average cloud cover in December: 56

The month with the most cloud cover is February (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 20).

Average visibility in December
Lebanon, OR

Average visibility in December - Lebanon, OR
  • Average visibility in December: 5mi

The months with the highest visibility are July, August and September (6mi).
The month with the lowest visibility is February (4mi).

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