Lake Granby — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Granby, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Granby today is 19.7°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 4 | 19.3°C | 17.5°C | |
| AUG 5 | 19.0°C | 17.5°C | |
| AUG 6 | 19.1°C | 17.5°C | |
| AUG 7 | 18.8°C | 17.5°C | |
| AUG 8 | 19.0°C | 17.5°C | |
| AUG 9 | 19.1°C | 17.5°C | |
| AUG 10 | 19.9°C | 17.5°C | |
| AUG 11 | 19.7°C | 17.5°C | |
| AUG 12 | 17.5°C | 19.6°C | |
| AUG 13 | 17.5°C | 19.5°C | |
| AUG 14 | 17.5°C | 19.4°C | |
| AUG 15 | 17.5°C | 19.3°C | |
| AUG 16 | 17.5°C | 19.2°C | |
| AUG 17 | 17.5°C | 19.0°C | |
| AUG 18 | 17.5°C | 18.9°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 | 1°C | 3°C | 6°C |
| February | 1°C | 3°C | 6°C |
| March | 3°C | 6°C | 9°C |
| April | 1°C | 5°C | 9°C |
| May | 4°C | 8°C | 13°C |
| June | 8°C | 12°C | 17°C |
| July | 14°C | 18°C | 22°C |
| August | 14°C | 18°C | 21°C |
| September | 11°C | 15°C | 18°C |
| October | 8°C | 12°C | 15°C |
| November | 5°C | 8°C | 11°C |
| December | 2°C | 6°C | 9°C |
Lake Granby: Water Temperature by Location
Lake Granby: Weather Forecast
August 12
August 13
August 14
August 15
August 16
Location & Local Information
Lake Granby is a high-elevation reservoir fed largely by snowmelt, so its water stays cool for most of the year. Surface temperatures typically hover near freezing in winter (around 32°F / 0°C), with the lake often forming ice. In spring and early summer the surface warms gradually, commonly ranging from roughly 35–50°F (2–10°C). On warm summer afternoons the shallow surface can reach about 60–68°F (15–20°C) in sheltered areas, but deeper water remains much colder year-round. During fall the surface cools back toward spring values as weather turns colder.
Swimming is generally possible in the warmer months, but it is limited by cold water and local rules or access points rather than an absolute prohibition. Because the reservoir is large, has boat traffic and few lifeguarded beaches, swimmers should exercise caution: cold-water shock and rapid loss of body heat are the primary hazards even when air temperatures are pleasant. Many visitors prefer shorter dips, wetsuits, or swimming in more protected, shallow bays when conditions allow. In winter the lake is not suitable for conventional swimming due to ice and near-freezing water temperatures.