In spring, when the air temperature is much higher than 0 ° С, the ice does not melt for a long time, and in autumn

In spring, when the air temperature is much higher than 0 ° С, the ice does not melt for a long time, and in autumn, when the air temperature is below 0 ° С, the water does not freeze immediately. Why?

This phenomenon is easily explained by the fact that water has a low thermal conductivity. So, for example, 4200 J is required to heat one liter of liquid, and 2100 J is required to melt one kilogram of ice. This is a significant amount of energy, because of this the ice does not melt immediately, and the water freezes gradually.