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Seattle in December

Find out everything about the water temperature in Seattle in December. Average, minimum and maximum recorded temperatures as well as daily temperature in December for the last two years. Compare the current month's sea temperature data with other months of the year.
Water temperature in December
Minimum:

46.9 °F

Average:

48.9 °F

Maximum:

51.3 °F

Sea water temperature in Seattle in December

In the city of Seattle, the month of December is too cold for swimming. The minimum recorded temperature during this month was 46.9°F on December 30, 2017, with an average temperature being 48.9°F and a maximum temperature reaching 51.3°F on December 2, 2021.

Swing in the water of such temperature might lead to potential hypothermia within just a few minutes. In December, the sea temperature remains relatively stable. The average temperature stays close to 48.9°F throughout the month, with minimal changes.
Date 10 years average 2023 2022
Dec 1 50.3°F 50.2°F 49.2°F
Dec 2 50.1°F 50.0°F 49.0°F
Dec 3 50.0°F 50.3°F 49.6°F
Dec 4 49.8°F 50.1°F 49.9°F
Dec 5 49.7°F 50.6°F 49.6°F
Dec 6 49.5°F 50.3°F 49.3°F
Dec 7 49.3°F 50.0°F 49.0°F
Dec 8 49.1°F 49.7°F 48.7°F
Dec 9 49.1°F 49.9°F 48.4°F
Dec 10 49.0°F 49.6°F 48.2°F
Dec 11 48.9°F 50.4°F 48.0°F
Dec 12 48.8°F 49.9°F 47.7°F
Dec 13 49.2°F 49.4°F 48.1°F
Dec 14 49.1°F 49.7°F 48.3°F
Dec 15 49.0°F 49.5°F 48.3°F
Dec 16 49.1°F 49.3°F 49.3°F
Dec 17 48.9°F 48.7°F 48.5°F
Dec 18 48.9°F 48.9°F 48.3°F
Dec 19 48.9°F 48.8°F 48.4°F
Dec 20 48.8°F 48.8°F 48.2°F
Dec 21 49.0°F 49.4°F 48.1°F
Dec 22 48.8°F 49.2°F 47.9°F
Dec 23 48.7°F 48.9°F 47.9°F
Dec 24 48.5°F 49.5°F 47.7°F
Dec 25 48.3°F 48.5°F 47.5°F
Dec 26 48.1°F 48.3°F 47.4°F
Dec 27 48.1°F 49.3°F 47.2°F
Dec 28 48.0°F 49.0°F 47.2°F
Dec 29 48.0°F 49.3°F 47.5°F
Dec 30 47.9°F 49.3°F 47.4°F
Dec 31 48.0°F 49.0°F 47.3°F

Sea water temperature in Seattle by month

In an average year, Seattle offers no days when the water temperature is warm enough to swim comfortably. The warmest water in Seattle was recorded on July 6, 2021, reaching a 63.4°F. While the coldest temperature occurred on February 5, 2014, dipping to 44.4°F. The average readings by season are 47.6°F in Winter, 49.6°F in Spring, 57.1°F in Summer, and 54.3°F in Autumn. December's average temperature is a slight drop from November's average of 51.7°F. In January, the temperature is expected to decrease further, potentially averaging around 47.3°F.