You no longer need to tell your little brat which season of the year it is. He is big enough to differentiate between the seasons and even enjoy them to the fullest.
What you need to know:
Though your kiddo can tell the difference he is certainly not aware of the importance of every season. Tell him how summers make us active and how winters make our body go lazy. Make him understand the implication of every season and the months that befall during the year. Most importantly, make the most of every season with him and let him enjoy.