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 18.5°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 65°F (18°C) to 68°F (20°C). This is already quite warm water, which is ideal for most people. Swimming becomes comfortable, and prolonged stays in the water do not cause discomfort. This temperature is perfect for family trips and for those who prefer warmer water. It is also comfortable for water sports such as surfing or swimming. 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 23 | 18.7°C | 18.0°C | |
| JUN 24 | 18.7°C | 18.0°C | |
| JUN 25 | 18.4°C | 18.0°C | |
| JUN 26 | 18.7°C | 18.0°C | |
| JUN 27 | 18.4°C | 18.0°C | |
| JUN 28 | 18.5°C | 18.0°C | |
| JUN 29 | 18.5°C | 18.0°C | |
| JUN 30 | 18.5°C | 18.0°C | |
| JUL 1 | 24.4°C | 18.8°C | |
| JUL 2 | 24.4°C | 19.1°C | |
| JUL 3 | 24.4°C | 19.4°C | |
| JUL 4 | 24.4°C | 19.7°C | |
| JUL 5 | 24.4°C | 20.0°C | |
| JUL 6 | 24.4°C | 20.3°C | |
| JUL 7 | 24.4°C | 20.6°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
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July 6
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.