December weather forecast
Prosser, WA

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Weather in December

December, the first month of the winter in Prosser, is also a wintry month, with temperature in the range of an average low of 27°F (-2.8°C) and an average high of 37.2°F (2.9°C).

Temperature

In Prosser, the month of December registers the lowest temperatures, averaging 37.2°F (2.9°C) at the peak and 27°F (-2.8°C) at the lowest.

Humidity

In Prosser, Washington, the average relative humidity in December is 79%.

Rainfall

The months with the most rainfall are January and December, with an average 0.94" (24mm) of precipitation.

Snowfall

January through March, September, November and December are months with snowfall in Prosser. In Prosser, during December, snow falls for 4.6 days and regularly aggregates up to 1.57" (40mm) of snow. Throughout the year, there are 13.5 snowfall days, and 5.87" (149mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 8h and 42min of daylight.
On the first day of the month, sunrise is at 7:22 am and sunset at 4:14 pm. On the last day of December, sunrise is at 7:41 am and sunset at 4:23 pm PST.

Sunshine

The average sunshine in December in Prosser, Washington, is 5.5h.

UV index

The months with the lowest UV index in Prosser are January, February, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for ordinary individuals.
Note: A daily high UV index of 2 in December leads to these guidelines:
Babies, children, and individuals with sensitive skin should always have protection against extended sun exposure. It's recommended to limit sun exposure when its radiation is at its peak during midday. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest in Prosser?

December stands out as Prosser's coldest month, with an average high-temperature of 37.2°F (2.9°C) and a low-temperature of 27°F (-2.8°C).

How cold is December in Prosser?

In December, in Prosser, the average high-temperature is 37.2°F (2.9°C), and the average low-temperature is 27°F (-2.8°C).

What is the average humidity in December in Prosser?

In Prosser, the average relative humidity in December is 79%.

What is the wettest month in Prosser?

The months with the most rainfall in Prosser are January and December, with an average 0.94" (24mm) of precipitation.

How many days does it rain in December in Prosser?

In December, in Prosser, Washington, the rain falls for 9.7 days. Throughout December, 0.94" (24mm) of precipitation is accumulated.

How much does it snow in Prosser in December?

In December, it is snowing for 4.6 days. Throughout December, 1.57" (40mm) of snow is accumulated.

What is the month with the shortest days in Prosser?

With an average of 8h and 42min of daylight, December has the shortest days of the year in Prosser, Washington.

What is the average length of the day in December in Prosser?

In December, the average day length is 8h and 41min.

What time are sunrise and sunset in December in Prosser?

On the first day of December in Prosser, sunrise is at 7:22 am and sunset at 4:14 pm. On the last day of the month, sunrise is at 7:41 am and sunset at 4:23 pm PST.

How long on average sun shines in December in Prosser?

In December, the average sunshine duration is 5.5h.

What are the months with the lowest UV index in Prosser?

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

What is the UV index intensity in December in Prosser?

In Prosser, Washington, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low health threat from 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
Prosser, WA

Average temperature in December - Prosser, WA
  • Average high temperature in December: 37.2°F

The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (37.2°F).

  • Average low temperature in December: 27°F

The month with the highest average low temperature is August (63.1°F).
The coldest month (with the lowest average low temperature) is December (27°F).

Average pressure in December
Prosser, WA

Average pressure in December - Prosser, 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).

Average wind speed in December
Prosser, WA

Average wind speed in December - Prosser, WA
  • Average wind speed in December: 5.6mph

The windiest month (with the highest average wind speed) is April (8.6mph).
The calmest month (with the lowest average wind speed) is December (5.6mph).

Average humidity in December
Prosser, WA

Average humidity in December - Prosser, WA
  • Average humidity in December: 79%

The month with the highest relative humidity is January (81%).
The months with the lowest relative humidity are July and August (37%).

Average rainfall in December
Prosser, WA

Average rainfall in December - Prosser, WA
  • Average rainfall in December: 0.94"

The wettest months (with the highest rainfall) are January and December (0.94").
The driest month (with the least rainfall) is July (0.2").

Average rainfall days in December
Prosser, WA

Average rainfall days in December - Prosser, WA
  • Average rainfall days in December: 9.7 days

The month with the highest number of rainy days is March (11.8 days).
The month with the least rainy days is July (3.6 days).

Average snowfall in December
Prosser, WA

Average snowfall in December - Prosser, WA
  • Average snowfall in December: 1.57"

The month with the highest snowfall is February (2.01").
The months with the least snowfall are April, May, June, July, August and October (0").

Average snowfall days in December
Prosser, WA

Average snowfall days in December - Prosser, WA
  • Average snowfall days in December: 4.6 days

The month with the highest number of snowfall days is December (4.6 days).
The months with the least snowfall days are April, May, June, July, August and October (0 days).

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

Average daylight in December / Average sunshine in December - Prosser, WA
  • Average daylight in December: 8h and 4min

The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).

  • Average sunshine in December: 5h and 3min

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

Average sunshine days in December
Prosser, WA

Average sunshine days in December - Prosser, WA
  • Average sunshine days in December: 16.5 days

The month with the most sunshine days is July (25.8 days).
The month with the least sunshine days is February (15.5 days).

Average UV index in December
Prosser, WA

Average UV index in December - Prosser, WA
  • 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
Prosser, WA

Average cloud cover in December - Prosser, WA
  • Average cloud cover in December: 44

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

Average visibility in December
Prosser, WA

Average visibility in December - Prosser, WA
  • 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).

Prosser, Washington, USA

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