December weather forecast
Hartline, WA

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Weather in December

The first month of the winter, December, is also a subzero cold month in Hartline, Washington, with temperature in the range of an average high of 31.6°F (-0.2°C) and an average low of 21.4°F (-5.9°C).

Temperature

December, marked by an average high-temperature of 31.6°F (-0.2°C) and a low-temperature of 21.4°F (-5.9°C), is the coldest month.

Humidity

The average relative humidity in December is 86%.

Rainfall

The wettest months are May and December, with an average 1.18" (30mm) of rainfall.

Snowfall

Months with snowfall in Hartline are January through April, September through December. In Hartline, during December, snow falls for 10.5 days and regularly aggregates up to 3.78" (96mm) of snow. Throughout the year, in Hartline, Washington, there are 33.4 snowfall days, and 14.65" (372mm) of snow is accumulated.

Daylight

With an average of 8h and 30min of daylight, December has the shortest days of the year in Hartline.
On the first day of the month, sunrise is at 7:24 am and sunset at 4:06 pm. On the last day of December, in Hartline, Washington, sunrise is at 7:44 am and sunset at 4:14 pm PST.

Sunshine

In December, the average sunshine is 4.4h.

UV index

In Hartline, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: An average maximum UV index of 2 in December leads to these recommendations:
Extended exposure to the sun should always be avoided by children, infants, and those with sensitive skin. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
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Frequently asked questions

What are the coldest months in Hartline?

In Hartline, December is the coldest month, with temperatures averaging a high of 31.6°F (-0.2°C) and a low of 21.4°F (-5.9°C).

How cold is December in Hartline?

An average high-temperature, in December, in Hartline, is 31.6°F (-0.2°C) and the average low-temperature is 21.4°F (-5.9°C).

What is the average humidity in December in Hartline?

In December, the average relative humidity is 86%.

What is the wettest month in Hartline?

The months with the most rainfall are May and December, with an average 1.18" (30mm) of precipitation.

How much does it rain in Hartline in December?

In December, the rain falls for 8.5 days. Throughout December, 1.18" (30mm) of precipitation is accumulated.

How many days does it snow in December in Hartline?

In Hartline, in December, snow falls for 10.5 days, with typically accumulated 3.78" (96mm) of snow.

What is the month with the shortest days in Hartline?

December has the shortest days of the year in Hartline, with an average of 8h and 30min of daylight.

How many hours of daylight does Hartline have in December?

In Hartline, the average day length in December is 8h and 29min.

When are sunrise and sunset in December in Hartline?

In December, on the first day of the month, sunrise is at 7:24 am and sunset at 4:06 pm. On the last day of the month, in Hartline, Washington, sunrise is at 7:44 am and sunset at 4:14 pm PST.

How long on average sun shines in December in Hartline?

In December, the average sunshine duration in Hartline, Washington, is 4.4h.

What is the UV index reading in December in Hartline?

In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes 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
Hartline, WA

Average temperature in December - Hartline, WA
  • Average high temperature in December: 31.6°F

The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (31.6°F).

  • Average low temperature in December: 21.4°F

The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).

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Average pressure in December
Hartline, WA

Average pressure in December - Hartline, WA
  • Average pressure in December: 30.15"Hg

The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).

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Average wind speed in December
Hartline, WA

Average wind speed in December - Hartline, WA
  • Average wind speed in December: 5mph

The windiest month (with the highest average wind speed) is April (7mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).

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Average humidity in December
Hartline, WA

Average humidity in December - Hartline, WA
  • Average humidity in December: 86%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (36%).

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Average rainfall in December
Hartline, WA

Average rainfall in December - Hartline, WA
  • Average rainfall in December: 1.18"

The wettest months (with the highest rainfall) are May and December (1.18").
The driest months (with the least rainfall) are July and August (0.2").

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Average rainfall days in December
Hartline, WA

Average rainfall days in December - Hartline, WA
  • Average rainfall days in December: 8.5 days

The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (3.2 days).

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Average snowfall in December
Hartline, WA

Average snowfall in December - Hartline, WA
  • Average snowfall in December: 3.78"

The month with the highest snowfall is January (4.41").
The months with the least snowfall are May, June, July and August (0").

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Average snowfall days in December
Hartline, WA

Average snowfall days in December - Hartline, WA
  • Average snowfall days in December: 10.5 days

The month with the highest number of snowfall days is December (10.5 days).
The months with the least snowfall days are May, June, July and August (0 days).

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Average daylight in December /
Average sunshine in December
Hartline, WA

Average daylight in December / Average sunshine in December - Hartline, WA
  • Average daylight in December: 8h and 3min

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

  • Average sunshine in December: 4h and 2min

The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

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Average sunshine days in December
Hartline, WA

Average sunshine days in December - Hartline, WA
  • Average sunshine days in December: 16 days

The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is March (14.7 days).

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Average UV index in December
Hartline, WA

Average UV index in December - Hartline, WA
  • Average UV index in December: 2

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is November (UV index 1).

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Average cloud cover in December
Hartline, WA

Average cloud cover in December - Hartline, WA
  • Average cloud cover in December: 52

The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and August (Cloud cover 12).

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Average visibility in December
Hartline, WA

Average visibility in December - Hartline, WA
  • Average visibility in December: 4mi

The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (4mi).

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Hartline, Washington, USA

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