Upper Saint Croix Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Upper Saint Croix Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Upper Saint Croix Lake 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 |
|---|---|---|---|
| JUN 6 | 16.8°C | 18.0°C | |
| JUN 7 | 17.2°C | 18.0°C | |
| JUN 8 | 19.8°C | 18.0°C | |
| JUN 10 | 20.0°C | 18.0°C | |
| JUN 11 | 20.2°C | 18.0°C | |
| JUN 12 | 20.2°C | 18.0°C | |
| JUN 13 | 19.7°C | 18.0°C | |
| JUN 14 | 18.0°C | 19.6°C | |
| JUN 15 | 18.0°C | 19.5°C | |
| JUN 16 | 18.0°C | 19.4°C | |
| JUN 17 | 18.0°C | 19.4°C | |
| JUN 18 | 18.0°C | 19.3°C | |
| JUN 19 | 18.0°C | 19.2°C | |
| JUN 20 | 18.0°C | 19.1°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 | 3°C | 7°C |
| February | 0°C | 3°C | 6°C |
| March | 0°C | 3°C | 7°C |
| April | 1°C | 6°C | 12°C |
| May | 6°C | 13°C | 19°C |
| June | 15°C | 18°C | 21°C |
| July | 20°C | 24°C | 27°C |
| August | 19°C | 25°C | 30°C |
| September | 14°C | 16°C | 19°C |
| October | 9°C | 14°C | 18°C |
| November | 2°C | 8°C | 13°C |
| December | 0°C | 3°C | 7°C |
Upper Saint Croix Lake: Water Temperature by Location
Upper Saint Croix Lake: Weather Forecast
June 13
June 14
June 15
June 16
June 17
June 18
Location & Local Information
Upper Saint Croix Lake in Wisconsin typically follows the seasonal temperature patterns of shallow northern lakes. In spring, as ice breaks up and air temperatures rise, surface water commonly ranges from about 45–60°F (7–16°C). Summer afternoons often produce the warmest readings, with surface temperatures usually between 68–78°F (20–26°C) in July and August, although shallow bays can warm a few degrees higher on calm, sunny days. By early autumn surface temperatures fall back into the mid-50s to low 70s°F (13–22°C) as cooling weather and increased mixing set in. In winter the lake is generally ice-covered and surface temperatures approach freezing around 32°F (0°C), with liquid water beneath the ice tending toward the typical near-4°C density maximum in deeper spots.
Swimming is generally allowed and is most common in summer when surface temperatures are comfortable for recreational use. Public access points and private shorelines offer places to enter the water, but seasonal factors influence safety and enjoyment: cold springs and sudden weather changes can make swimming hazardous, and late-summer algae or shoreline runoff occasionally affect water quality. In winter, swimming is not safe under normal conditions once ice forms, except for organized ice-swimming activities conducted with appropriate safety measures. Always check local advisories and conditions before entering the water.