Half Moon Bay — Water Temperature, Sea Conditions & Trends

Water Temperature: Daily Trends, Historical Records, and Forecast

⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people.

It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.

Water Temperature Chart Over the Last 30 Days

Currently, the sea water temperature at this location matches the average for this day in previous years.

According to our forecast, Water temperature in Half Moon Bay will be 16.2°C in the next 7 days. See the table below for daily data for the upcoming week.

Table of Daily Sea Temperature Data

Annual Water Temperature Overview by Month

Monthly Water Temp Ranges

30°C

25°C

20°C

15°C

10°c

5°C

0°C

Annual Water Temperature Trend

Half Moon Bay, on the central California coast south of San Francisco, fronts the cold eastern Pacific and experiences relatively cool sea temperatures year-round. Typical sea surface temperatures range from about 8°C in the coldest winter months to roughly 15°C in the warmest late-summer and early-fall period. Most of the year the water averages near 10–14°C, and local upwelling can push temperatures lower even during summer, so conditions can shift noticeably from day to day depending on wind and ocean currents.