When was the last winter in Westeros?

At the beginning of the books, when Bran is 7 years old, it's noted that it's the ninth year of summer. So assuming that there was a spring before that summer, it has to have been at least nine years since the last winter. read more

The last winter in Westeros ended more than 9 years before the beginning of the first book. It wasn't a very long one - probably only a year or so. Robert's Rebellion, which took place about 14 years before the beginning of the books, was during the end of the previous winter/beginning of spring. read more

There isn't any specific duration. It varies. For example,the current summer has lasted 10 years; there has been a 7 year summer. Also, there is a mention of a 3 year winter etc. Usually they say that 'the longer the summer, the longer the winter' 2. If I remember correctly, none of the Stark children have ever seen a winter. read more