Santa Margarita Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Santa Margarita Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Santa Margarita Lake today is 18.5°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 | 19.8°C | 21.1°C | |
| OCT 27 | 20.1°C | 21.1°C | |
| OCT 28 | 19.8°C | 21.1°C | |
| OCT 29 | 19.8°C | 21.1°C | |
| OCT 30 | 19.5°C | 21.1°C | |
| OCT 31 | 19.4°C | 21.1°C | |
| NOV 1 | 18.8°C | 16.5°C | |
| NOV 2 | 18.5°C | 16.5°C | |
| NOV 3 | 16.5°C | 18.4°C | |
| NOV 4 | 16.5°C | 18.3°C | |
| NOV 5 | 16.5°C | 18.2°C | |
| NOV 6 | 16.5°C | 18.1°C | |
| NOV 7 | 16.5°C | 18.0°C | |
| NOV 8 | 16.5°C | 17.9°C | |
| NOV 9 | 16.5°C | 17.8°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 | 10°C | 12°C | 15°C |
| February | 9°C | 11°C | 14°C |
| March | 6°C | 13°C | 20°C |
| April | 15°C | 19°C | 21°C |
| May | 16°C | 20°C | 23°C |
| June | 18°C | 21°C | 24°C |
| July | 21°C | 24°C | 27°C |
| August | 22°C | 25°C | 28°C |
| September | 20°C | 23°C | 26°C |
| October | 19°C | 21°C | 24°C |
| November | 13°C | 17°C | 20°C |
| December | 11°C | 14°C | 17°C |
Santa Margarita Lake: Water Temperature by Location
Santa Margarita Lake: Weather Forecast
November 3
November 4
November 5
November 6
November 7
Location & Local Information
Santa Margarita Lake, a reservoir in coastal-central California, tends to have cool to moderately warm surface temperatures that vary by season. In summer, sheltered shallows can warm to roughly 65–80°F (18–27°C) on sunny days, while most open-water surfaces more commonly sit in the mid-60s°F (about 18–20°C). Spring and fall bring cooler conditions, typically in the 50–65°F range (10–18°C). During winter the lake’s surface often falls to about 45–55°F (7–13°C), and deeper water remains substantially colder year-round because of thermal stratification; even in summer, sudden dips into deeper areas can expose swimmers to near-freezing shock relative to surface temperatures.
Swimming at Santa Margarita Lake is generally discouraged or restricted, primarily because the reservoir serves as a managed water resource and for safety considerations. Restrictions are intended to protect water quality for downstream use and to reduce public-health risks such as contamination or harmful algal blooms. Safety concerns include cold-water shock, steep drop-offs, submerged hazards and boat traffic, all of which raise the risk for accidental injury. Where recreational access is permitted, most visitors use the lake for boating and fishing in designated areas rather than open-water swimming, and anyone choosing to enter the water should verify current rules and exercise caution.