Why Does Snow Sometimes Struggle To Accumulate On The Road Even At 32 Degrees?

New York City Manhattan resident here. It has been a snowy February. However, other than the big snowstorm at the start of the month, the majority of the snow accumulations have been limited to bridges, car tops, and grassy areas. One day, I noticed that the air temperature was 32 degrees and the snowfall rate was falling between 0.5 to 1.0 inches per hour. That day saw about 8 inches of snow. I did notice that on the roads, the snow was just mainly slushy even though the temperature was at the freezing mark. Why is that? Also, is there a huge difference between 33 and 32 degrees when it comes to accumulating snow? I think that once you drop below 31, 30, or 29 degrees, snow will stick everywhere regardless of the snowfall rate. I have noticed occasionally that snow can accumulate on the streets even when the temperature is as high as 35, 36, or even 40 degrees when the snowfall rate pushed 2 to 3 inches per hour. Honestly, I am a bit jealous of the suburbs of Northern New Jersey and the Catskills that seem to get the most snow and hold on to the white stuff longer. In New York City, after a few days, the snow turns black except in Central Park. I am guessing that the cars driving in the city streets are responsible for making the snow turn black. Also, the fact that Manhattan is not as cold as The Adirondacks. How much snow do the Adirondacks get?