I'm the other way around. I live in Arizona and have bad allergies, but when I go back home to Wisconsin, my allergies totally clear up.
Allergies develop over time and you can get new allergies, too. Maybe yours got worse or you developed a new one. Allergists are pretty awesome. The can often isolate your trigger and treat you over time to stop your body from reacting to whatever it is. In my case, I'm allergic to virtually everything, so that's out, but if you get tested and only have a couple of triggers, you may be able to cure the allergies entirely.