Lake Whatcom — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Whatcom, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Whatcom 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 |
|---|---|---|---|
| AUG 24 | 19.3°C | 23.5°C | |
| AUG 25 | 19.0°C | 23.5°C | |
| AUG 26 | 19.0°C | 23.5°C | |
| AUG 27 | 19.1°C | 23.5°C | |
| AUG 28 | 19.0°C | 23.5°C | |
| AUG 29 | 18.8°C | 23.5°C | |
| AUG 30 | 19.2°C | 23.5°C | |
| AUG 31 | 19.1°C | 23.5°C | |
| SEP 1 | 21.0°C | 18.6°C | |
| SEP 2 | 21.0°C | 18.8°C | |
| SEP 3 | 21.0°C | 18.9°C | |
| SEP 4 | 21.0°C | 19.0°C | |
| SEP 5 | 21.0°C | 19.1°C | |
| SEP 6 | 21.0°C | 19.3°C | |
| SEP 7 | 21.0°C | 19.4°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 | 3°C | 7°C |
| February | 2°C | 5°C | 8°C |
| March | 4°C | 8°C | 11°C |
| April | 6°C | 11°C | 15°C |
| May | 9°C | 15°C | 21°C |
| June | 13°C | 19°C | 24°C |
| July | 15°C | 23°C | 31°C |
| August | 17°C | 24°C | 30°C |
| September | 16°C | 21°C | 26°C |
| October | 11°C | 16°C | 20°C |
| November | 5°C | 10°C | 14°C |
| December | 4°C | 7°C | 9°C |
Lake Whatcom: Water Temperature by Location
Lake Whatcom: Weather Forecast
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September 4
September 5
September 6
Location & Local Information
Lake Whatcom is a relatively cool, deep lake, and surface water temperatures change noticeably through the year. Typical seasonal surface ranges are roughly 35–45°F (2–7°C) in winter, 45–60°F (7–16°C) in spring, 60–72°F (15–22°C) in midsummer, and 50–60°F (10–16°C) in fall. Because the lake is fairly deep and shaded by forested shorelines, the hypolimnion (deep water) stays much colder year-round, even during summer, so overall temperatures remain lower than many shallower inland lakes in warmer regions.
Swimming is allowed in designated recreational areas along Lake Whatcom, and people commonly swim during the warmest weeks of July and August when surface temperatures peak. However, parts of the lake lie within a municipal watershed supplying drinking water to Bellingham, and those zones have restrictions intended to protect water quality; some activities are limited or prohibited there. Swimmers should be mindful of cold-water shock risk, variable conditions, and local rules; using supervised or established beaches is the recommended way to swim safely while respecting watershed protections.