December weather forecast
Heppner, OR

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Weather in December

The first month of the winter, December, is still a cold month in Heppner, Oregon, with an average temperature varying between 37.9°F (3.3°C) and 27.1°F (-2.7°C).

Temperature

With average high and low temperatures of 37.9°F (3.3°C) and 27.1°F (-2.7°C) respectively, December is Heppner's coldest month.

Humidity

In December, the average relative humidity is 78%.

Rainfall

In Heppner, Oregon, during December, the rain falls for 12.8 days and regularly aggregates up to 1.65" (42mm) of precipitation. Throughout the year, there are 131.9 rainfall days, and 13.54" (344mm) of precipitation is accumulated.

Snowfall

January through May, September through December are months with snowfall. In December, it is snowing for 9.2 days. Throughout December, 3.66" (93mm) of snow is accumulated. In Heppner, Oregon, during the entire year, snow falls for 31.3 days and aggregates up to 18.54" (471mm) of snow.

Daylight

With an average of 8h and 48min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:18 am and sunset at 4:16 pm. On the last day of December, sunrise is at 7:37 am and sunset at 4:25 pm PST.

Sunshine

In December, the average sunshine is 5.4h.

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 value of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum UV index of 2 during December leads to these instructions:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Enhance your sun protection with tightly woven, yet airy clothing. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months?

December, with average temperatures reaching a high of 37.9°F (3.3°C) and a low of 27.1°F (-2.7°C), is the coldest month.

Is December cold?

The high-temperature, in December, in Heppner, is 37.9°F (3.3°C), while the low-temperature averages to 27.1°F (-2.7°C).

What is the average humidity in December?

In Heppner, the average relative humidity in December is 78%.

How many days does it rain in December?

In Heppner, during December, the rain falls for 12.8 days and regularly aggregates up to 1.65" (42mm) of precipitation.

How much does it snow in December?

In Heppner, in December, snow falls for 9.2 days, with typically accumulated 3.66" (93mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 8h and 48min of daylight.

What is the average length of the day in December?

In Heppner, the average day length in December is 8h and 48min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 7:18 am and sunset at 4:16 pm. On the last day of the month, sunrise is at 7:37 am and sunset at 4:25 pm PST.

How long on average sun shines in December?

The average sunshine duration in December is 5.4h.

What is the month with the lowest UV index?

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

How high is the UV index in December in Heppner?

In Heppner, the average daily maximum UV index in December is 2. A UV Index reading 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
Heppner, OR

Average temperature in December - Heppner, OR
  • Average high temperature in December: 37.9°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is December (37.9°F).

  • Average low temperature in December: 27.1°F

The month with the highest average low temperature is August (60.8°F).
The coldest month (with the lowest average low temperature) is December (27.1°F).

Average pressure in December
Heppner, OR

Average pressure in December - Heppner, OR
  • Average pressure in December: 30.17"Hg

The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.92"Hg).

Average wind speed in December
Heppner, OR

Average wind speed in December - Heppner, OR
  • Average wind speed in December: 8mph

The windiest month (with the highest average wind speed) is April (9.4mph).
The calmest month (with the lowest average wind speed) is September (7.2mph).

Average humidity in December
Heppner, OR

Average humidity in December - Heppner, OR
  • Average humidity in December: 78%

The month with the highest relative humidity is January (79%).
The months with the lowest relative humidity are July and August (39%).

Average rainfall in December
Heppner, OR

Average rainfall in December - Heppner, OR
  • Average rainfall in December: 1.65"

The wettest month (with the highest rainfall) is February (1.81").
The driest month (with the least rainfall) is July (0.24").

Average rainfall days in December
Heppner, OR

Average rainfall days in December - Heppner, OR
  • Average rainfall days in December: 12.8 days

The month with the highest number of rainy days is March (17 days).
The month with the least rainy days is August (4.1 days).

Average snowfall in December
Heppner, OR

Average snowfall in December - Heppner, OR
  • Average snowfall in December: 3.66"

The month with the highest snowfall is February (6.61").
The months with the least snowfall are June, July and August (0").

Average snowfall days in December
Heppner, OR

Average snowfall days in December - Heppner, OR
  • Average snowfall days in December: 9.2 days

The month with the highest number of snowfall days is December (9.2 days).
The months with the least snowfall days are June, July and August (0 days).

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

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

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in December: 5h and 2min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and February (Average sunshine: 5h and 18min).

Average sunshine days in December
Heppner, OR

Average sunshine days in December - Heppner, OR
  • Average sunshine days in December: 12.8 days

The month with the most sunshine days is July (24.4 days).
The month with the least sunshine days is March (9.5 days).

Average UV index in December
Heppner, OR

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

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December
Heppner, OR

Average cloud cover in December - Heppner, OR
  • Average cloud cover in December: 45

The months with the most cloud cover are January and February (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 9).

Average visibility in December
Heppner, OR

Average visibility in December - Heppner, OR
  • 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).

Heppner, Oregon, USA

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