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 12.4°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 54°F (12°C) to 60°F (15°C). The water is significantly warmer, and swimming becomes possible for most people. However, caution may still be required for prolonged stays in the water, as extended exposure can cause discomfort. This is a suitable temperature range for short swims and for those accustomed to cooler water. For more comfortable swimming, it is recommended to use proper gear. 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 5 | 14.8°C | 13.5°C | |
| OCT 6 | 14.9°C | 13.5°C | |
| OCT 7 | 14.4°C | 13.5°C | |
| OCT 8 | 13.0°C | 13.5°C | |
| OCT 9 | 13.4°C | 13.5°C | |
| OCT 10 | 13.4°C | 13.5°C | |
| OCT 11 | 12.3°C | 13.5°C | |
| OCT 12 | 12.5°C | 13.5°C | |
| OCT 13 | 13.5°C | 12.5°C | |
| OCT 14 | 13.5°C | 12.5°C | |
| OCT 15 | 13.5°C | 12.6°C | |
| OCT 16 | 13.5°C | 12.6°C | |
| OCT 17 | 13.5°C | 12.7°C | |
| OCT 18 | 13.5°C | 12.7°C | |
| OCT 19 | 13.5°C | 12.8°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
October 13
October 14
October 15
October 16
October 17
October 18
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.