December weather forecastSeaside, OR

December
Weather in December
December in Seaside, Oregon, bears witness to the return of snowfall with 0.04" (1mm), albeit sparingly, indicating the commencement of winter. Sunshine hours drop lowest in the year, offering limited warmth during the day. The landscape transforms with stark trees and frost-kissed plains, portraying a picture of winter wonderland in parts. Alongside the plummeting temperatures, wind speeds steal away much of the warmth, marking an unpreventable welcome to winter. Therefore, December heralds a cold but festive closure to the year.Temperature
Temperature readings reach their annual highs in December, averaging 46.6°F (8.1°C) and a minimum average of 40.5°F (4.7°C).Humidity
The months with the lowest humidity in Seaside are January, March through May, October and December, with an average relative humidity of 81%.Rainfall
December is the month with the most rainfall. Rain falls for 20.7 days and accumulates 6.54" (166mm) of precipitation.Snowfall
Months with snowfall are January through March and December. December is the first month it typically snows. Throughout December, in the average 0.3 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 2.8 snowfall days, and 1.3" (33mm) of snow is accumulated.Ocean temperature
In Seaside, in December, the average water temperature is 50°F (10°C).Note: Swimming in 50°F (10°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.
Daylight
December has the shortest days of the year, with an average of 8h and 42min of daylight.On the first day of the month, sunrise is at 7:37 am and sunset at 4:32 pm. On the last day of December, sunrise is at 7:57 am and sunset at 4:40 pm PST.
Sunshine
The average sunshine in December is 4.2h.UV index
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 low threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: In December, the maximum UV index of 2 suggests these recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Seaside, OR
- Average high temperature in December: 46.6°F
The warmest month (with the highest average high temperature) is August (65.5°F).
The month with the lowest average high temperature is December (46.6°F).
- Average low temperature in December: 40.5°F
The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is December (40.5°F).
Average pressure in December
Seaside, OR
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is January (30.08"Hg).
The months with the lowest atmospheric pressure are March and September (30.02"Hg).
Average wind speed in December
Seaside, OR
- Average wind speed in December: 10.5mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in December
Seaside, OR
- Average humidity in December: 81%
The month with the highest relative humidity is August (84%).
The months with the lowest relative humidity are January, March, April, May, October and December (81%).
Average rainfall in December
Seaside, OR
- Average rainfall in December: 6.54"
The wettest month (with the highest rainfall) is December (6.54").
The driest months (with the least rainfall) are July and August (0.47").
Average rainfall days in December
Seaside, OR
- Average rainfall days in December: 20.7 days
The month with the highest number of rainy days is March (20.8 days).
The months with the least rainy days are July and August (7.3 days).
Average snowfall in December
Seaside, OR
- Average snowfall in December: 0.04"
The month with the highest snowfall is February (0.59").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in December
Seaside, OR
- Average snowfall days in December: 0.3 days
The month with the highest number of snowfall days is February (1.3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature in December
Seaside, OR
- Average sea temperature in December: 49.9°F
The best month for swimming (with the highest average sea temperature) is July (57.2°F).
The coldest month (with the lowest average sea temperature) is February (48.1°F).
Average daylight in December /
Average sunshine in December
Seaside, OR
- Average daylight in December: 8h and 42min
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: 4h and 12min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The months with the least sunshine are January and February (Average sunshine: 3h and 54min).
Average sunshine days in December
Seaside, OR
- Average sunshine days in December: 8.8 days
The month with the most sunshine days is August (21.2 days).
The month with the least sunshine days is February (7.5 days).
Average UV index in December
Seaside, OR
- Average UV index in December: 2
The months with the highest UV index are May, June, July, August and September (UV index 4).
The months with the lowest UV index are February, November and December (UV index 2).
Average cloud cover in December
Seaside, OR
- Average cloud cover in December: 56
The months with the most cloud cover are January and February (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 35).
Average visibility in December
Seaside, OR
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, September, October, November and December (6mi).
The month with the lowest visibility is August (5mi).





