Upper Otay Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Upper Otay Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Upper Otay Lake today is 30.4°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature is above 82°F (28°C). This is very warm water, which may feel almost hot to most people. Swimming in such conditions is perfect for those seeking relaxation and comfort in the water. These waters are often preferred for relaxation in hot weather, as the water temperature does not cool the body significantly. However, it is important to remember that in such warm waters, caution is necessary, as prolonged exposure without rest can lead to overheating. 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 |
|---|---|---|---|
| JUL 14 | 27.5°C | 29.6°C | |
| JUL 15 | 31.4°C | 29.6°C | |
| JUL 16 | 31.4°C | 29.6°C | |
| JUL 17 | 31.2°C | 29.6°C | |
| JUL 18 | 31.2°C | 29.6°C | |
| JUL 19 | 31.4°C | 29.6°C | |
| JUL 20 | 31.5°C | 29.6°C | |
| JUL 21 | 30.8°C | 29.6°C | |
| JUL 22 | 29.6°C | 30.4°C | |
| JUL 23 | 29.6°C | 30.3°C | |
| JUL 24 | 29.6°C | 30.3°C | |
| JUL 25 | 29.6°C | 30.2°C | |
| JUL 26 | 29.6°C | 30.2°C | |
| JUL 27 | 29.6°C | 30.2°C | |
| JUL 28 | 29.6°C | 30.1°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 | 33°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 |
Upper Otay Lake: Water Temperature by Location
Upper Otay Lake: Weather Forecast
July 22
July 23
July 24
July 25
July 26
Location & Local Information
Upper Otay Lake, the upper reservoir in the Otay Lakes area near San Diego, experiences mild to warm surface temperatures that change with the seasons. In winter months the water commonly cools into the lower 50s to around 60°F (about 10–15°C). Spring sees a gradual rise, with surface readings often in the mid-50s to mid-60s°F (13–18°C). By summer the top layer of the lake frequently warms to the upper 60s into the upper 70s°F (roughly 20–26°C), and on hot, calm days shallow areas can be a few degrees warmer. In autumn temperatures generally decline back toward the 60–70°F range (16–21°C). Deeper water remains noticeably cooler year-round, and the lake can develop thermoclines that create abrupt temperature changes with depth.
Swimming in Upper Otay Lake is generally not permitted for the public. As a managed reservoir, access and recreational uses are restricted to protect water quality, support reservoir operations, and reduce safety risks from submerged structures, boat traffic, and sudden cold water below the surface. Even where water recreation is allowed nearby, the combination of variable temperatures, hidden hazards, and reservoir management policies makes organized swimming uncommon; visitors should consult local park or water agency rules and follow posted restrictions and safety guidance.