Calero Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Calero Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Calero Reservoir today is 29°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 | 25.4°C | 26.1°C | |
| JUL 15 | 29.2°C | 26.1°C | |
| JUL 16 | 29.2°C | 26.1°C | |
| JUL 17 | 29.2°C | 26.1°C | |
| JUL 18 | 29.2°C | 26.1°C | |
| JUL 19 | 28.8°C | 26.1°C | |
| JUL 20 | 28.9°C | 26.1°C | |
| JUL 21 | 28.9°C | 26.1°C | |
| JUL 22 | 26.1°C | 28.9°C | |
| JUL 23 | 26.1°C | 28.7°C | |
| JUL 24 | 26.1°C | 28.6°C | |
| JUL 25 | 26.1°C | 28.4°C | |
| JUL 26 | 26.1°C | 28.3°C | |
| JUL 27 | 26.1°C | 28.1°C | |
| JUL 28 | 26.1°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 | 8°C | 10°C | 13°C |
| February | 5°C | 9°C | 13°C |
| March | 8°C | 14°C | 21°C |
| April | 15°C | 17°C | 20°C |
| May | 16°C | 21°C | 25°C |
| June | 21°C | 25°C | 29°C |
| July | 23°C | 26°C | 30°C |
| August | 23°C | 26°C | 28°C |
| September | 21°C | 25°C | 28°C |
| October | 18°C | 22°C | 26°C |
| November | 13°C | 18°C | 21°C |
| December | 10°C | 12°C | 15°C |
Calero Reservoir: Water Temperature by Location
Calero Reservoir: Weather Forecast
July 22
July 23
July 24
July 25
July 26
Location & Local Information
Calero Reservoir (sometimes referred to as Calero Lake) in Santa Clara County typically stays cool year-round compared with coastal beaches. Surface temperatures in spring commonly range from about 50–65°F (10–18°C) as runoff and cooler air linger. In summer the warmest surface readings often reach roughly 60–75°F (16–24°C) on sunny, calm days, though deeper or shaded areas remain cooler. Fall temperatures usually sit between 55–70°F (13–21°C) as the water slowly releases stored heat, and winter surface values commonly fall to roughly 45–55°F (7–13°C), with colder pockets after frontal storms. These figures are approximate; actual temperatures depend on depth, recent weather, and inflows.
Swimming at Calero Reservoir is generally not encouraged and may be restricted by park authorities. The reservoir is managed primarily for recreation and watershed purposes, and safety and water-quality concerns — including cold water shock, steep banks, submerged hazards, limited visibility, and the absence of lifeguards — lead officials to prohibit or discourage open swimming. Boating and shoreline fishing are common alternatives. Visitors should follow posted rules and county park guidance before entering the water, since local regulations and seasonal advisories determine whether swimming is permitted.