Lower Otay Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lower Otay Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lower Otay Lake today is 27.4°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 | 28.2°C | 29.0°C | |
| SEP 16 | 27.4°C | 29.0°C | |
| SEP 17 | 27.6°C | 29.0°C | |
| SEP 18 | 27.5°C | 29.0°C | |
| SEP 19 | 27.6°C | 29.0°C | |
| SEP 20 | 27.2°C | 29.0°C | |
| SEP 21 | 27.3°C | 29.0°C | |
| SEP 22 | 29.0°C | 27.5°C | |
| SEP 23 | 29.0°C | 27.6°C | |
| SEP 24 | 29.0°C | 27.6°C | |
| SEP 25 | 29.0°C | 27.7°C | |
| SEP 26 | 29.0°C | 27.8°C | |
| SEP 27 | 29.0°C | 27.9°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 | 11°C | 14°C | 18°C |
| February | 12°C | 16°C | 20°C |
| March | 14°C | 19°C | 24°C |
| April | 17°C | 22°C | 26°C |
| May | 20°C | 22°C | 25°C |
| June | 20°C | 24°C | 28°C |
| July | 25°C | 30°C | 34°C |
| August | 27°C | 30°C | 34°C |
| September | 26°C | 29°C | 32°C |
| October | 21°C | 24°C | 26°C |
| November | 17°C | 22°C | 26°C |
| December | 14°C | 17°C | 19°C |
Lower Otay Lake: Water Temperature by Location
Lower Otay Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
Location & Local Information
Lower Otay Lake is a man-made reservoir in southern San Diego County and its surface water temperatures vary with the seasons and local weather. In winter the lake commonly cools to roughly 48–58°F (9–14°C), while spring typically brings a gradual rise into the mid 50s to mid 60s °F (13–18°C). Summer surface readings can reach the warmest values, often about 62–75°F (17–24°C) on calm sunny days, and autumn usually sees a decline into the upper 50s to low 70s °F (14–21°C). Because the reservoir is fed by runoff and can have sudden thermoclines and deeper, colder layers, surface measurements can change quickly with wind, shade and inflow events.
Swimming in Lower Otay Lake is generally not permitted; the reservoir functions as a municipal water supply and the local water district restricts human contact to protect water quality and public health. In addition to regulatory limits, safety concerns such as cold temperatures in deeper sections, steep drop-offs, submerged hazards and boat traffic make unsupervised bathing risky. Recreational access is focused on permitted boating and fishing in designated areas where rules and seasonal conditions are posted and enforced to balance recreation with the need to safeguard the drinking water resource.