I marked the correction as wrong, because to me ''It rains often here'' sounds perfectly acceptable in English. I've probably said this exact sentence hundreds of times, since I live in a rainy part of the country.
It might be a colloquial way of speaking. but when I did a search on the sentence in Google, there were some 3,000 examples, including a number of them in books.
http://www.doublebrush.com/2007/10/the-rainiest-ci.html I know of what I speak.