Keyhole Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Keyhole Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Keyhole Reservoir today is 17.8°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 |
|---|---|---|---|
| JUN 3 | 18.4°C | 18.0°C | |
| JUN 4 | 18.1°C | 18.0°C | |
| JUN 5 | 18.3°C | 18.0°C | |
| JUN 6 | 18.7°C | 18.0°C | |
| JUN 7 | 18.7°C | 18.0°C | |
| JUN 8 | 17.8°C | 18.0°C | |
| JUN 11 | 18.0°C | 17.8°C | |
| JUN 12 | 18.0°C | 17.8°C | |
| JUN 13 | 18.0°C | 17.8°C | |
| JUN 14 | 18.0°C | 17.8°C | |
| JUN 15 | 18.0°C | 17.9°C | |
| JUN 16 | 18.0°C | 17.9°C | |
| JUN 17 | 18.0°C | 17.9°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 | 0°C | 1°C | 4°C |
| February | 0°C | 1°C | 4°C |
| March | 0°C | 3°C | 7°C |
| April | 4°C | 8°C | 12°C |
| May | 7°C | 13°C | 20°C |
| June | 14°C | 18°C | 22°C |
| July | 22°C | 24°C | 27°C |
| August | 21°C | 25°C | 28°C |
| September | 16°C | 19°C | 21°C |
| October | 8°C | 13°C | 17°C |
| November | 3°C | 7°C | 10°C |
| December | 0°C | 2°C | 5°C |
Keyhole Reservoir: Water Temperature by Location
Keyhole Reservoir: Weather Forecast
June 9
June 10
June 11
June 12
June 13
Location & Local Information
Keyhole Reservoir in northeastern Wyoming experiences a wide range of water temperatures through the year due to its northerly latitude, elevation and the influence of seasonal weather. In spring (roughly April–May) surface readings commonly run from about 40–55°F (4–13°C) as snowmelt and cooler air keep the lake chilly. By early summer (June) temperatures typically rise into the mid-50s to upper‑60s °F (13–20°C), with peak summer (July–August) surface waters often reaching roughly 60–75°F (15–24°C) on warm, calm days. As autumn progresses the surface cools again, commonly moving back through the 45–65°F (7–18°C) range, and in winter the reservoir can freeze or sit just above freezing with surface water near 32°F (0°C) under ice conditions.
Swimming at Keyhole is generally possible and the reservoir is used for recreation, but it is not uniformly supervised and conditions vary. Designated shoreline areas and coves are commonly used for bathing, yet fluctuating water levels, wind-driven waves, and boat traffic can create hazards. Cooler shoulder-season temperatures and deep water mean there is a real risk of cold‑water shock and hypothermia even in summer mornings or cloudy weather, so swimmers should be cautious, wear flotation when appropriate, and heed local signage and management rules.