Curing time in summer is less than that in winter. Why?

While concrete sets, it gains hardness and strength as the process of hydration slowly spreads the entire body of material. Curing should be allowed to continue for several days before subjecting the new concrete to significant stress. The period of curing depends on the temperature because the rate of all chemical reactions is dependent on temperature. Therefore, in summer the rate of reaction (hydration) is faster so that a shorter curing time is required. On the contrary, in winter the rate of reaction (hydration) is slower so that a longer curing time is required.

This question is taken from book named – A Closer Look at Prevailing Civil Engineering Practice – What, Why and How by Vincent T. H. CHU.