Green Bay — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Green Bay, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Green Bay today is 5°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
❌ As of today, the minimum water temperature ranges less than 41°F (5°C). Such water is extremely cold and not recommended for swimming without proper preparation. In these conditions, the risk of hypothermia is very high, and prolonged exposure to the water can be hazardous to your health. If you decide to swim, it is important to have the appropriate gear, such as a wetsuit. Typically, only experienced swimmers or those who practice winter swimming venture into such waters. 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 |
|---|---|---|---|
| OCT 26 | 11.6°C | 13.5°C | |
| OCT 27 | 11.5°C | 13.5°C | |
| OCT 28 | 11.6°C | 13.5°C | |
| OCT 29 | 10.2°C | 13.5°C | |
| OCT 30 | 10.7°C | 13.5°C | |
| OCT 31 | 12.2°C | 13.5°C | |
| NOV 1 | 11.7°C | 4.5°C | |
| NOV 2 | 5.0°C | 4.5°C | |
| NOV 3 | 4.5°C | 5.0°C | |
| NOV 4 | 4.5°C | 5.0°C | |
| NOV 5 | 4.5°C | 4.9°C | |
| NOV 6 | 4.5°C | 4.9°C | |
| NOV 7 | 4.5°C | 4.9°C | |
| NOV 8 | 4.5°C | 4.9°C | |
| NOV 9 | 4.5°C | 4.8°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 | 4°C | 7°C |
| February | 1°C | 5°C | 8°C |
| March | 0°C | 3°C | 5°C |
| April | 2°C | 6°C | 11°C |
| May | 7°C | 15°C | 23°C |
| June | 16°C | 19°C | 22°C |
| July | 17°C | 23°C | 29°C |
| August | 20°C | 24°C | 27°C |
| September | 12°C | 18°C | 24°C |
| October | 9°C | 14°C | 18°C |
| November | 0°C | 5°C | 9°C |
| December | 0°C | 2°C | 5°C |
Green Bay: Water Temperature by Location
Green Bay: Weather Forecast
November 3
November 4
November 5
November 6
November 7
Location & Local Information
Green Bay, the broad inlet of Lake Michigan along Wisconsin’s shoreline, experiences a wide range of surface water temperatures through the year. In winter the bay often chills to near freezing, roughly 32–39°F (0–4°C), and in cold years sheltered areas may ice over. Spring brings gradual warming into the 40s and 50s°F (4–15°C), while summer surface temperatures typically reach the mid-60s to mid-70s°F (18–24°C) and can occasionally hit the upper 70s°F (25–26°C) in warm, shallow spots. By autumn the water cools back into the 50s–60s°F (10–16°C) as the season progresses. These seasonal ranges vary with wind, depth, and local weather patterns; shallower nearshore waters warm and cool faster than deeper channels.
Swimming is generally allowed at public beaches and recreational areas along Green Bay, and many communities post designated swim beaches during the warmer months. Authorities may close or advise against swimming for reasons such as high bacterial counts after heavy rains, periodic harmful algal blooms, strong currents, or cold-water hypothermia risk outside summer. Lifeguard coverage and water-quality monitoring are seasonal, so swimmers should follow posted guidance; in summer the temperatures are most comfortable, while shoulder seasons and winter are unsafe for casual swimming due to cold and potential ice.