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 27.3°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 | 27.8°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 | 27.0°C | 29.0°C | |
| SEP 19 | 27.6°C | 29.0°C | |
| SEP 20 | 27.7°C | 29.0°C | |
| SEP 21 | 27.3°C | 29.0°C | |
| SEP 22 | 29.0°C | 27.4°C | |
| SEP 23 | 29.0°C | 27.5°C | |
| SEP 24 | 29.0°C | 27.6°C | |
| SEP 25 | 29.0°C | 27.6°C | |
| SEP 26 | 29.0°C | 27.7°C | |
| SEP 27 | 29.0°C | 27.8°C | |
| SEP 28 | 29.0°C | 27.9°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 |
Upper Otay Lake: Water Temperature by Location
Upper Otay Lake: Weather Forecast
September 21
September 22
September 23
September 24
September 25
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.