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

54.6

°F

October 6, 20:33

Trend:

stable

Yesterday:

53.8°F

Tomorrow:

54.6°F

Sunrise:

07:18

Sunset:

18:51

Day Length:

11 h. 33 min.

Eureka in October

Minimum:

50.5°F

Average:

52.3°F

Maximum:

54.1°F

Sea water temperature in Eureka today

As of now, in Eureka, the water temperature is 54.6°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 0.3°F higher than the average recorded on this particular day in recent years. Since yesterday, there was a slight increase in temperature. This indicates a warming trend over the past day. According to the forecast, we expect the temperature to stay about the same.

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 56.5°F on 2020, while the historical minimum was 52.9°F on 2024.

Over the past two weeks, the water temperature has closely aligned with historical averages for those days. The forecast for the upcoming week shows a gradual cooling trend. The average temperature is expected to be 54.1°F, the minimum temperature may reach 53.2°F, and the maximum might stay at 54.8°F.

Daily water temperature in Eureka

Date Current Year

actual* / forecast**

last year 10 years average
Sep 22 55.6°F 55.6°F 55.7°F
Sep 23 55.7°F 56.7°F 55.7°F
Sep 24 54.8°F 56.9°F 55.5°F
Sep 25 54.8°F 56.7°F 55.5°F
Sep 26 55.3°F 54.6°F 55.4°F
Sep 27 55.0°F 55.9°F 55.6°F
Sep 28 55.2°F 55.8°F 55.4°F
Sep 29 54.9°F 55.8°F 55.0°F
Sep 30 55.3°F 55.0°F 55.1°F
Oct 1 55.5°F 54.9°F 54.9°F
Oct 2 55.8°F 55.8°F 54.8°F
Oct 3 55.7°F 56.1°F 54.8°F
Oct 4 55.5°F 57.9°F 54.8°F
Oct 5 53.8°F 56.9°F 54.5°F
Oct 6 54.6°F 56.4°F 54.4°F
Oct 7 54.6°F 56.0°F 54.3°F
Oct 8 54.8°F 56.6°F 54.6°F
Oct 9 54.3°F 56.3°F 54.1°F
Oct 10 54.3°F 55.4°F 54.0°F
Oct 11 53.9°F 55.3°F 53.7°F
Oct 12 53.3°F 54.7°F 53.0°F
Oct 13 53.2°F 54.0°F 53.0°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 52.0°F in Winter, 51.3°F in Spring, 53.6°F in Summer, and 54.2°F in Autumn.