Lake Mathews — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Mathews, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Mathews today is 27.5°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 79°F (26°C) to 82°F (28°C). This is very warm water, allowing for extended stays without any discomfort. Swimming in these conditions will be particularly enjoyable, making it the ideal temperature range for those who want to relax in the sea. Additionally, water in this temperature range is suitable for children and elderly people, as it is comfortable for prolonged stays. 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 |
|---|---|---|---|
| SEP 14 | 27.7°C | 29.0°C | |
| SEP 15 | 27.8°C | 29.0°C | |
| SEP 16 | 27.5°C | 29.0°C | |
| SEP 17 | 27.8°C | 29.0°C | |
| SEP 18 | 27.6°C | 29.0°C | |
| SEP 19 | 28.0°C | 29.0°C | |
| SEP 20 | 27.3°C | 29.0°C | |
| SEP 21 | 27.5°C | 29.0°C | |
| SEP 22 | 29.0°C | 27.6°C | |
| SEP 23 | 29.0°C | 27.7°C | |
| SEP 24 | 29.0°C | 27.7°C | |
| SEP 25 | 29.0°C | 27.8°C | |
| SEP 26 | 29.0°C | 27.9°C | |
| SEP 27 | 29.0°C | 28.0°C | |
| SEP 28 | 29.0°C | 28.0°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.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 13°C | 22°C | 30°C |
| February | 12°C | 20°C | 27°C |
| March | 14°C | 23°C | 31°C |
| April | 17°C | 24°C | 31°C |
| May | 19°C | 26°C | 31°C |
| June | 21°C | 26°C | 30°C |
| July | 25°C | 30°C | 33°C |
| August | 27°C | 30°C | 33°C |
| September | 26°C | 29°C | 32°C |
| October | 24°C | 26°C | 29°C |
| November | 16°C | 22°C | 27°C |
| December | 14°C | 19°C | 22°C |
Lake Mathews: Water Temperature by Location
Lake Mathews: Weather Forecast
September 21
September 22
September 23
September 24
September 25
Location & Local Information
Lake Mathews is a deep, inland reservoir in Southern California whose surface water temperature follows the region’s seasonal cycles. In winter months surface temperatures commonly sit in the low 50s to low 60s °F (about 11–17 °C), while spring and fall typically bring mid-60s to low 70s °F (18–23 °C). During summer the warmest surface readings are often in the mid 70s to low 80s °F (24–28 °C), though sheltered bays and shallow areas can warm slightly more on hot, calm days. Because the reservoir is relatively deep, water below the surface can remain significantly cooler year-round, and daily sun and wind conditions can cause short-term fluctuations in the top layer’s temperature.
Swimming at Lake Mathews is not permitted. The site is operated primarily as a municipal drinking-water reservoir and access is restricted to protect water quality and public safety; allowing recreational swimming would increase contamination risk and complicate reservoir management. In addition, the reservoir’s limited public facilities, variable underwater conditions, and restricted shoreline make organized recreation impractical. Any water-contact activities around Lake Mathews are therefore tightly controlled, and visitors should assume that typical open-water swimming opportunities available at other public lakes are not allowed there.