What clematis is this?

[butterflycatcher]

I am looking for a climber to bring a bit of spring colour to the front of the house. Is this a clematis Montana? Reading up on this variety it says it flowers May to June but this plant in a neighbours garden has been in flower for April. The timing is quite important as I have roses that will flower in May/June so want to get something before this period.

It is Montana, mine is in flower now.

Thanks @Mmmkaay is it typically in flower at this time or could this be down to the milder March getting things moving earlier?

No it's usually around now, sometimes sooner! Definitely gone before the roses.

One of mine has just started to flower, the other which gets less sun will be later.