This is the exact same way you would normally find the darkest parts of the image when you're removing any color casts from the shadow areas, but now, thanks to the Difference blend mode, these darkest areas represent the areas closest to midtone gray.
The warmest sea in Key Largo in March is 26Â°C/79Â°F, and the coldest sea temperature in March is 22Â°C/72Â°F. Average water temperature in Key Largo in March is 24Â°C/75Â°F. You can choose any other years:
Water Temperature Key Largo: 7 Day Forecast. Due to the tropical climate it enjoys all year round, Key Largo is a comfortably warm place to visit any time of the year. The average summer temperature is 89 degrees, but this is made comfortable by cooling ocean waters. In the winter temperatures hover around 75 to 80 degrees, with occasional warmer days.