Clematis Montana, should flower early in the year in spring, I think you are a little mixed up dear.

 I cut her well back after she finished flowering because she had swamped the old archway and was stopping me getting into the rest of the garden and I wanted to put the new archway up. Since then she has decided to attack the house and is trying to pull the drainpipe down now!

A quick view through the new archway before it gets swamped again.