Other forms: acclimatized; acclimatizing; acclimatizes
When you get used to a new situation or climate, you acclimatize to it. People who travel to very hot countries in the summer find it takes quite some time to acclimatize to the heat.
The verb acclimatize is usually followed by the word "to," and while you can use it to essentially mean "get used to the weather," it can also refer to new situations. A new student will acclimatize to her new school, and an African immigrant will need to acclimatize to many unfamiliar conditions in the US. Acclimatize comes from acclimate, and in many cases has replaced it — both come from a French root, acclimater.