All data are in degrees Fahrenheit

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Water temperature in Eureka

Detailed information about the current water temperature in Eureka. The trend over the last two weeks, daily averages, and precise forecast of the water temperature changes. Gain a deeper understanding of seasonal dynamics with monthly statistical analyses covering recent years.
Sea temperature in Eureka now

52.6

°F

January 16, 02:34

Trend:

stable

Yesterday:

52.7°F

Tomorrow:

52.7°F

Sunrise:

07:39

Sunset:

17:15

Day Length:

9 h. 36 min.

Eureka in January

Minimum:

50.4°F

Average:

52.1°F

Maximum:

54.7°F

Sea water temperature in Eureka today

As of now, in Eureka, the water temperature is 52.6°F. Swimming in water of this temperature is considered as extremely cold, and there's a substantial risk of hypothermia if exposed for more than a brief duration. Today's reading is 0.5°F higher than the average recorded on this particular day in recent years. The sea temperature remains approximately unchanged from yesterday. According to the forecast, we expect the temperature to rise a bit.

Recent sea temperature and forecast

Today's water temperature is slightly lower than the average registered over the last two weeks, indicating a slight cooling trend. It also aligns closely with the historical average temperature for this date, indicating a typical climate pattern. The maximum temperature recorded for this date was 53.5°F on 2024, while the historical minimum was 50.4°F on 2025.

Over the last two weeks, the water temperature has stayed slightly above than historical averages for those days. Over the next week, the forecast shows a steady trend, with temperatures staying close to the average of 52.5°F. Both minimum and maximum temperatures expected to be close to the average, offering a week of stable water conditions.

Daily water temperature in Eureka

Date Current Year

actual* / forecast**

last year 10 years average
Jan 2 52.5°F 53.7°F 52.3°F
Jan 3 52.7°F 53.6°F 52.2°F
Jan 4 53.4°F 53.7°F 52.2°F
Jan 5 53.6°F 53.5°F 52.1°F
Jan 6 53.8°F 53.4°F 52.2°F
Jan 7 53.5°F 53.2°F 52.3°F
Jan 8 53.8°F 53.4°F 52.3°F
Jan 9 53.7°F 53.3°F 52.4°F
Jan 10 53.2°F 53.0°F 52.3°F
Jan 11 53.4°F 53.2°F 52.3°F
Jan 12 53.4°F 52.3°F 52.2°F
Jan 13 52.9°F 50.9°F 52.1°F
Jan 14 52.7°F 49.6°F 52.1°F
Jan 15 52.7°F 50.2°F 52.2°F
Jan 16 52.6°F 50.4°F 52.2°F
Jan 17 52.7°F 50.7°F 52.3°F
Jan 18 52.7°F 50.8°F 52.2°F
Jan 19 52.6°F 50.3°F 52.2°F
Jan 20 52.5°F 50.1°F 52.1°F
Jan 21 52.3°F 49.6°F 51.9°F
Jan 22 52.4°F 49.4°F 51.9°F
Jan 23 52.3°F 49.1°F 51.9°F

* actual - actual temperature values

** forecast - projected values for the next week

Real-time coastal temperatures could deviate by several degrees from the provided readings. These deviations often become evident following intense rainfall or strong winds.

Our forecasting methodology leverages a mathematical model, that uses current water and weather conditions, historical records, wind intensity and direction.

Sea water temperature in Eureka by month

In an average year, Eureka offers no days when the water temperature is warm enough to swim comfortably.
The warmest water in Eureka was recorded on August 12, 2022, reaching a 61.8°F. While the coldest temperature occurred on June 7, 2025, dipping to 44.2°F. The average readings by season are 51.9°F in Winter, 51.2°F in Spring, 53.7°F in Summer, and 54.2°F in Autumn.