What does this sentence mean?
"The further you travel from the equator in either direction the more the seasons assert themselves and you get colder and darker winters, making summer time much more valuable to the locals. "

Although I know the meaning of 'assert', I can't understand 'the seasons assert themselves.' What does it mean?

Thanks!

Question

What does this sentence mean?
"The further you travel from the equator in either direction the more the seasons assert themselves and you get colder and darker winters, making summer time much more valuable to the locals. "

Although I know the meaning of 'assert', I can't understand 'the seasons assert themselves.' What does it mean?

Thanks!

Answer

In laymen's terms "The further north or south you go from the equator, the more the seasons have a stronger effect on the weather." That was the troublesome part, right?

"Assert" in this case means to "to impose" or "make more prominent." Hopefully, that helped you.

Answer

There are two fixed expressions: if sombody asserts himself, he/she  expresses him-/herself confidently and forcefully; and if something asserts itself, it exerts strong influence over something else.

Answer

Seasons assert themselves = become stronger, more pronounced, more distinct

('assert' is used here as a figure of speech, IMHO, it's the personification of seasons, which cannot really assert themselves in the regular meaning of this verb)