Why was my hair texture different when I went to a colder climate?

My hair is curly and it is melting hot in mexico but when I went to the states....all of the sudden it was straightish?





Is that normal?Why does this occur?Why was my hair texture different when I went to a colder climate?
The amount of humidity in the air affects hair.Why was my hair texture different when I went to a colder climate?
When it's more humid hair tends to curl, but the lack of humidity makes hair straighter.