Castaic Lagoon — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Castaic Lagoon, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Castaic Lagoon today is 19.7°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 26 | 22.1°C | 22.8°C | |
| OCT 27 | 22.1°C | 22.8°C | |
| OCT 28 | 21.7°C | 22.8°C | |
| OCT 29 | 21.3°C | 22.8°C | |
| OCT 30 | 20.7°C | 22.8°C | |
| OCT 31 | 21.0°C | 22.8°C | |
| NOV 1 | 20.9°C | 18.8°C | |
| NOV 2 | 19.7°C | 18.8°C | |
| NOV 3 | 18.8°C | 19.7°C | |
| NOV 4 | 18.8°C | 19.6°C | |
| NOV 5 | 18.8°C | 19.6°C | |
| NOV 6 | 18.8°C | 19.5°C | |
| NOV 7 | 18.8°C | 19.5°C | |
| NOV 8 | 18.8°C | 19.4°C | |
| NOV 9 | 18.8°C | 19.4°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 | 8°C | 11°C | 15°C |
| February | 9°C | 13°C | 17°C |
| March | 10°C | 15°C | 20°C |
| April | 14°C | 17°C | 21°C |
| May | 17°C | 21°C | 25°C |
| June | 21°C | 24°C | 27°C |
| July | 22°C | 27°C | 31°C |
| August | 25°C | 29°C | 32°C |
| September | 24°C | 28°C | 31°C |
| October | 20°C | 23°C | 25°C |
| November | 16°C | 19°C | 22°C |
| December | 11°C | 15°C | 19°C |
Castaic Lagoon: Water Temperature by Location
Castaic Lagoon: Weather Forecast
November 3
November 4
November 5
November 6
November 7
Location & Local Information
Castaic Lagoon, part of the Castaic Lake recreational area in northern Los Angeles County, tends to have mild to cool water temperatures that vary by season and depth. In winter the surface water commonly sits around the low 50s to low 60s °F (about 10–17 °C). Spring temperatures climb into the mid-50s to mid-60s °F (13–19 °C) as air temperatures warm. In summer and early fall the shallow swim areas warm the most, with typical surface readings in the low 70s to upper 70s °F (about 21–26 °C); on hot, calm days shallow pockets can briefly reach the low 80s °F (≈27–28 °C). These are approximate ranges and actual conditions change with weather, shading and water level.
Swimming is allowed in the designated lagoon area and is managed as a recreational swim site, often with lifeguards and clear boundaries to separate it from the larger reservoir. The main Castaic reservoir has more restrictions because of safety concerns and its role as part of the regional water system, so public bathing is generally limited to the maintained lagoon. Even in summer, swimmers should be aware that deeper water can remain significantly colder than surface readings, so caution is advised.