Lewis Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lewis Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lewis Lake today is 17.9°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 |
|---|---|---|---|
| AUG 24 | 19.1°C | 18.0°C | |
| AUG 25 | 18.7°C | 18.0°C | |
| AUG 26 | 18.6°C | 18.0°C | |
| AUG 27 | 18.5°C | 18.0°C | |
| AUG 28 | 18.6°C | 18.0°C | |
| AUG 29 | 19.6°C | 18.0°C | |
| AUG 30 | 19.1°C | 18.0°C | |
| AUG 31 | 18.9°C | 18.0°C | |
| SEP 1 | 14.5°C | 17.7°C | |
| SEP 2 | 14.5°C | 17.6°C | |
| SEP 3 | 14.5°C | 17.4°C | |
| SEP 4 | 14.5°C | 17.2°C | |
| SEP 5 | 14.5°C | 17.1°C | |
| SEP 6 | 14.5°C | 16.9°C | |
| SEP 7 | 14.5°C | 16.7°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 | 4°C | 6°C |
| February | 1°C | 4°C | 7°C |
| March | 1°C | 5°C | 9°C |
| April | 0°C | 3°C | 5°C |
| May | 2°C | 6°C | 11°C |
| June | 7°C | 11°C | 14°C |
| July | 9°C | 16°C | 21°C |
| August | 14°C | 18°C | 22°C |
| September | 11°C | 15°C | 18°C |
| October | 4°C | 8°C | 12°C |
| November | 2°C | 6°C | 10°C |
| December | 1°C | 4°C | 7°C |
Lewis Lake: Water Temperature by Location
Lewis Lake: Weather Forecast
September 1
September 2
September 3
September 4
September 5
Location & Local Information
Lewis Lake, located in the high country of Wyoming’s Teton region, is a classic mountain lake with water temperatures that reflect its elevation, seasonal snowmelt and cool alpine climate. In spring (May–June) surface temperatures commonly sit between about 35–50°F (2–10°C) as snowmelt feeds the lake and warming is limited. By mid to late summer (July–August) the warmest months, sheltered bays and sun-warmed surface layers can reach roughly 55–68°F (13–20°C) on a typical year, though deeper water remains much colder. Early fall (September) temperatures generally fall back to about 45–60°F (7–15°C) as nights cool and inflows increase, and in winter the lake is often ice-covered with water at or just above freezing, around 32–39°F (0–4°C) beneath the ice.
Swimming at Lewis Lake is permitted in the sense that there are no formal bans, but practical safety considerations strongly affect whether people choose to enter the water. The lake’s high elevation, cold temperatures even in summer, and rapidly changing mountain weather mean hypothermia is a real risk; there are no lifeguards or extensive beach facilities, and boat traffic can be present. Short dips or swims using thermal protection like a wetsuit are the usual approach for those who enter the water, while most visitors enjoy the shoreline, fishing and views rather than prolonged immersion.