Horsetooth Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Horsetooth Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Horsetooth Reservoir today is 20°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 |
|---|---|---|---|
| AUG 26 | 26.8°C | 25.3°C | |
| AUG 27 | 27.8°C | 25.3°C | |
| AUG 28 | 27.5°C | 25.3°C | |
| AUG 29 | 27.5°C | 25.3°C | |
| AUG 30 | 27.5°C | 25.3°C | |
| AUG 31 | 27.4°C | 25.3°C | |
| SEP 1 | 27.4°C | 23.2°C | |
| SEP 2 | 27.4°C | 23.2°C | |
| SEP 3 | 23.2°C | 20.2°C | |
| SEP 4 | 23.2°C | 20.3°C | |
| SEP 5 | 23.2°C | 20.5°C | |
| SEP 6 | 23.2°C | 20.6°C | |
| SEP 7 | 23.2°C | 20.8°C | |
| SEP 8 | 23.2°C | 21.0°C | |
| SEP 9 | 23.2°C | 21.1°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 | 2°C | 5°C |
| March | 0°C | 5°C | 11°C |
| April | 4°C | 10°C | 15°C |
| May | 8°C | 14°C | 20°C |
| June | 16°C | 20°C | 24°C |
| July | 21°C | 25°C | 30°C |
| August | 21°C | 25°C | 30°C |
| September | 19°C | 23°C | 28°C |
| October | 14°C | 17°C | 20°C |
| November | 7°C | 11°C | 14°C |
| December | 2°C | 5°C | 8°C |
Horsetooth Reservoir: Water Temperature by Location
Horsetooth Reservoir: Weather Forecast
September 3
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September 5
September 6
September 7
Location & Local Information
Horsetooth Reservoir, west of Fort Collins, typically shows a pronounced seasonal cycle in water temperature. In spring the surface usually runs cool, roughly 45–60°F (7–16°C) as runoff dominates, then warms through early summer to about 60–70°F (15–21°C). Peak summer surface readings often reach the low to mid 70s°F (21–26°C) in sheltered bays and shallower areas, and can occasionally climb into the upper 70s or around 80°F (26–27°C) on very warm, calm spells. By autumn the surface cools again, commonly falling to the 50s–60s°F (10–16°C) in early fall and dropping into the 40s–50s°F (4–10°C) later on; winter temperatures approach freezing, typically around 32–45°F (0–7°C).
Swimming is permitted in parts of Horsetooth but is not universally supervised, and there are important caveats. Designated shorelines and park swim spots are used for bathing in summer, but swimmers face hazards including cold-water shock from sudden temperature changes, steep drop-offs, boat traffic, and occasional harmful algal blooms that can prompt temporary closures. Lifeguards are generally not provided, so swimming is at one’s own risk and best done with precautions: checking current conditions, staying near shore, and avoiding cold, early-season water or areas with heavy boating.