California Delta Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in California Delta Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in California Delta Lake today is 19.8°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 65°F (18°C) to 68°F (20°C). This is already quite warm water, which is ideal for most people. Swimming becomes comfortable, and prolonged stays in the water do not cause discomfort. This temperature is perfect for family trips and for those who prefer warmer water. It is also comfortable for water sports such as surfing or swimming. 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
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| OCT 5 | 19.6°C | 21.0°C | |
| OCT 6 | 19.9°C | 21.0°C | |
| OCT 7 | 19.6°C | 21.0°C | |
| OCT 8 | 19.4°C | 21.0°C | |
| OCT 9 | 19.4°C | 21.0°C | |
| OCT 10 | 19.6°C | 21.0°C | |
| OCT 11 | 20.4°C | 21.0°C | |
| OCT 12 | 20.2°C | 21.0°C | |
| OCT 13 | 21.0°C | 19.9°C | |
| OCT 14 | 21.0°C | 19.9°C | |
| OCT 15 | 21.0°C | 20.0°C | |
| OCT 16 | 21.0°C | 20.0°C | |
| OCT 17 | 21.0°C | 20.1°C | |
| OCT 18 | 21.0°C | 20.2°C | |
| OCT 19 | 21.0°C | 20.2°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.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 6°C | 9°C | 12°C |
| February | 6°C | 10°C | 14°C |
| March | 9°C | 15°C | 21°C |
| April | 14°C | 17°C | 21°C |
| May | 17°C | 21°C | 26°C |
| June | 21°C | 24°C | 27°C |
| July | 21°C | 25°C | 30°C |
| August | 21°C | 26°C | 32°C |
| September | 19°C | 23°C | 28°C |
| October | 17°C | 21°C | 25°C |
| November | 12°C | 16°C | 19°C |
| December | 8°C | 11°C | 14°C |
California Delta Lake: Water Temperature by Location
California Delta Lake: Weather Forecast
October 13
October 14
October 15
October 16
October 17
October 18
Location & Local Information
The inland waterways of California’s Sacramento–San Joaquin Delta and its associated lakes and sloughs tend to be cooler than coastal beach water in the summer and noticeably cold in winter. Typical surface temperatures vary by season and by depth and exposure: winter surface values commonly sit around 45–55°F (7–13°C), spring often warms to roughly 55–65°F (13–18°C), summer can raise shallow, sunlit areas into the mid‑60s to upper‑70s °F (about 18–26°C), and early fall sometimes remains in the mid‑50s to mid‑70s °F (13–24°C). Local conditions such as recent inflows, wind, and solar heating can change temperatures considerably over short distances or days.
Swimming is physically possible in many Delta lakes and channels, but it is often unofficial and subject to caution. Water quality can be variable—urban and agricultural runoff, bacterial contamination, and periodic harmful algal blooms may prompt advisories—so swimmers should check current alerts before entering. Other considerations include heavy boat traffic, strong currents in channels, submerged debris, and the lack of lifeguards at most sites. As a result, while recreational swimming occurs, it is best approached with awareness of seasonal temperatures, local advisories, and personal safety measures.