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:
Florida Keys: Annual Weather Averages. July is the hottest month in Florida Keys with an average temperature of 30Â°C (86Â°F) and the coldest is January at 21Â°C (70Â°F) with the most daily sunshine hours at 10 in May. The wettest month is September with an average of 149mm of rain. The best month to swim in the sea is in July when the average sea temperature is 31Â°C (88Â°F).