Big Sage Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Big Sage Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Big Sage Reservoir today is 15.1°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people. 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 | 17.2°C | 21.0°C | |
| SEP 15 | 16.3°C | 21.0°C | |
| SEP 16 | 15.9°C | 21.0°C | |
| SEP 17 | 15.7°C | 21.0°C | |
| SEP 18 | 15.9°C | 21.0°C | |
| SEP 19 | 16.1°C | 21.0°C | |
| SEP 20 | 15.8°C | 21.0°C | |
| SEP 21 | 15.1°C | 21.0°C | |
| SEP 22 | 21.0°C | 15.4°C | |
| SEP 23 | 21.0°C | 15.7°C | |
| SEP 24 | 21.0°C | 16.0°C | |
| SEP 25 | 21.0°C | 16.3°C | |
| SEP 26 | 21.0°C | 16.6°C | |
| SEP 27 | 21.0°C | 16.9°C | |
| SEP 28 | 21.0°C | 17.2°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 | 0°C | 2°C | 5°C |
| February | 1°C | 3°C | 6°C |
| March | 2°C | 5°C | 8°C |
| April | 4°C | 8°C | 11°C |
| May | 10°C | 16°C | 20°C |
| June | 17°C | 21°C | 25°C |
| July | 19°C | 22°C | 26°C |
| August | 22°C | 24°C | 27°C |
| September | 18°C | 21°C | 24°C |
| October | 10°C | 14°C | 18°C |
| November | 3°C | 7°C | 10°C |
| December | 0°C | 2°C | 4°C |
Big Sage Reservoir: Water Temperature by Location
Big Sage Reservoir: Weather Forecast
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Big Sage Reservoir’s surface water temperatures change a lot through the year. In winter the lake commonly chills into the 40s–50°F (4–10°C), often cold enough to discourage extended immersion. Spring and fall tend to bring moderate surface readings around 50–65°F (10–18°C) as runoff and air temperatures shift. In the warmest weeks of summer the surface can warm to roughly 60–75°F (16–24°C), though this depends on weather, shading and elevation; deeper water remains substantially cooler year‑round, often staying in the 40s–50s°F (4–12°C) below the thermocline.
Swimming at Big Sage Reservoir is generally possible where public access is allowed, but conditions and rules vary so it’s important to check local signage and landowner restrictions before entering the water. Cold temperatures, sudden drop‑offs and the absence of lifeguards make unguarded swimming potentially hazardous, and boat traffic or occasional algal blooms can further limit safe areas. Because water may be used for irrigation or other purposes, some shores or coves can be off limits. Visitors should assess water clarity and temperature, wear a life jacket if boating, and avoid prolonged immersion in cold water to reduce the risk of cold‑water shock and hypothermia.