Frenchman Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Frenchman Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Frenchman Lake today is 15.3°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 25 | 18.0°C | 20.6°C | |
| SEP 26 | 18.0°C | 20.6°C | |
| SEP 27 | 17.8°C | 20.6°C | |
| SEP 28 | 17.5°C | 20.6°C | |
| SEP 29 | 16.8°C | 20.6°C | |
| SEP 30 | 16.9°C | 20.6°C | |
| OCT 1 | 16.5°C | 15.0°C | |
| OCT 2 | 15.1°C | 15.0°C | |
| OCT 3 | 15.0°C | 15.3°C | |
| OCT 4 | 15.0°C | 15.3°C | |
| OCT 5 | 15.0°C | 15.3°C | |
| OCT 6 | 15.0°C | 15.2°C | |
| OCT 7 | 15.0°C | 15.2°C | |
| OCT 8 | 15.0°C | 15.2°C | |
| OCT 9 | 15.0°C | 15.2°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 | 0°C | 3°C | 5°C |
| March | 0°C | 4°C | 9°C |
| April | 0°C | 4°C | 9°C |
| May | 8°C | 12°C | 16°C |
| June | 13°C | 17°C | 21°C |
| July | 18°C | 22°C | 25°C |
| August | 20°C | 23°C | 25°C |
| September | 18°C | 21°C | 23°C |
| October | 11°C | 15°C | 19°C |
| November | 4°C | 9°C | 12°C |
| December | 0°C | 3°C | 6°C |
Frenchman Lake: Water Temperature by Location
Frenchman Lake: Weather Forecast
October 3
October 4
October 5
October 6
October 7
Location & Local Information
Frenchman Lake is a high‑elevation reservoir in northern California, so water temperatures tend to be cool most of the year. Typical surface temperatures in spring range from roughly 40–55°F (4–13°C) as snowmelt and runoff dominate. In mid to late summer, when air temperatures warm, the surface can warm to approximately 60–70°F (15–21°C), with occasional warmer days pushing readings into the low 70s (about 22–23°C) in shallow, sheltered spots. By fall the lake cools back toward 45–60°F (7–16°C), and in winter the surface often approaches freezing or develops ice along the edges, roughly 32–40°F (0–4°C), depending on conditions and elevation.
Swimming is generally allowed at Frenchman Lake because it is managed as a public recreation area, and people commonly enter the water for brief swims and paddling. However, the combination of persistently cool temperatures, lack of lifeguards, steep drop‑offs, and potential for cold‑water shock means swimming is not without risk. Visitors are advised to swim only in daylight, stay close to shore, wear flotation when appropriate, and heed posted rules or seasonal closures; the lake’s suitability for comfortable swimming is typically limited to the warmest weeks of summer.