Two consecutive days and very different underfoot. My impression was that the air temperature was about the same each day but we were sliding along on sheet ice in the top picture. The top picture came with gale force winds. It was flat calm in the bottom picture. My hypothesis is evaporative cooling. The wind keeps shifting particles away from the surface. This would lead to higher rates of evaporation for water. It is the most energetic particles that escape first. Those that remain have lower energy therefore the temperature is lower and would thus be more likely to freeze.
