Half Moon Bay — Water Temperature, Sea Conditions & Trends
This page provides clear and up-to-date information about water temperature for Half Moon Bay (California, United States). It includes the current water temperature, daily data for the last month presented in a simple chart, and a 7-day forecast. The page also compares today’s value with typical averages for this period, shows usual monthly ranges during the year, and lists nearby beaches with short descriptions. Local weather for the next few days and general details about Half Moon Bay help you plan your visit and choose the best time for swimming.
Current Water Temperature
Water temperature in Half Moon Bay in the Pacific Ocean today is 13°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
❌ As of today, the minimum water temperature ranges from 54°F (12°C) to 60°F (15°C). The water is significantly warmer, and swimming becomes possible for most people. However, caution may still be required for prolonged stays in the water, as extended exposure can cause discomfort. This is a suitable temperature range for short swims and for those accustomed to cooler water. For more comfortable swimming, it is recommended to use proper gear.
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
Water temperature in Half Moon Bay today is lower than both a week ago and a month ago. 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 14.0°C in the next 7 days. See the table below for daily data for the upcoming week.
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| JUN 5 | 13.5°C | 13.3°C | |
| JUN 6 | 13.8°C | 13.0°C | |
| JUN 7 | 13.8°C | 13.8°C | |
| JUN 8 | 14.0°C | 13.0°C | |
| JUN 9 | 13.6°C | 13.3°C | |
| JUN 10 | 13.4°C | 12.8°C | |
| JUN 11 | 12.4°C | 12.8°C | |
| JUN 12 | 12.3°C | 13.3°C | |
| JUN 13 | 12.8°C | 13.3°C | 12.8°C |
| JUN 14 | 14.0°C | 13.0°C | |
| JUN 15 | 14.0°C | 13.1°C | |
| JUN 16 | 14.0°C | 13.3°C | |
| JUN 17 | 14.3°C | 13.5°C | |
| JUN 18 | 13.5°C | 13.7°C | |
| JUN 19 | 14.0°C | 13.8°C | |
| JUN 20 | 13.8°C | 14.0°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.
Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.
Water temperature data for this location is gathered from various sources, including buoys and satellite sea and ocean surface maps provided by the NOAA agency. We also incorporate data from local authorities in each specific location worldwide to ensure more accurate temperature readings.
Annual Water Temperature Overview by Month
Monthly Water Temp Ranges
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.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 9°C | 12°C | 15°C |
| February | 10°C | 12°C | 15°C |
| March | 10°C | 12°C | 15°C |
| April | 10°C | 13°C | 16°C |
| May | 10°C | 13°C | 17°C |
| June | 9°C | 14°C | 17°C |
| July | 11°C | 15°C | 18°C |
| August | 12°C | 15°C | 18°C |
| September | 13°C | 16°C | 18°C |
| October | 12°C | 16°C | 18°C |
| November | 11°C | 13°C | 18°C |
| December | 10°C | 12°C | 16°C |
* Click on a month to view detailed water temperature data.
Half Moon Bay: Weather Forecast
June 13
June 14
June 15
June 16
Location, Beaches & Local Information
Nearby Beaches & Facilities
Half Moon Bay State Beach - Francis Beach
Poplar Beach
Half Moon Bay State Beach - Elmar Beach
Half Moon Bay State Beach - Venice Beach
Redondo Beach
Half Moon Bay State Beach - Dunes Beach
Venice State Beach
Half Moon Bay State Beach - Roosevelt Beach
Wavecrest Beach
Swimming Conditions
Swimming opportunities at Half Moon Bay are available but modest compared with warmer destinations. Protected stretches and sandy coves permit wading, short swims and calmer paddling, while more exposed beaches produce stronger surf and rip currents that suit experienced surfers and bodyboarders rather than casual swimmers. Because the water is chilly, many visitors choose wetsuits for comfort and longer time in the water; seasonal lifeguard coverage exists at some popular beaches but not everywhere, so caution is advised. The area still makes for an enjoyable beach holiday with coastal walkways, tidepools, picnic areas and water-sport rentals, but most swimming tends to be brief or combined with wetsuit-supported activities like surfing, kayaking or stand-up paddleboarding.