in the summer, in summer
In the winter (summer, spring) , in winter (summer, spring), which one is more common when used in general, not for a particular winter?
Is this a British English American English thing? Or one is more formal than the other?

Question

Answer

Mostly, I think you can do either, but not always.

In summer I like to go swimming. Sounds natural to me.
In the summer I like to go swimming. Still OK but sounds less natural to me.

I like to go swimming in the summer. Sounds natural to me. 
I like to go swimming in summer. Sounds unnatural to me.

I am from the UK.

Answer

Maybe you're right. Rhythm.

Answer

Good question. I'm not sure, and I think I use both. Perhaps the choice is about rhythm?