What size are your containers David?

sorry moon growe should have said,they about 20insx20ins,don"t do metric. thanks very much.

So a reasonable size, you could try Heuchera, Euonymus,Photinia, Ceanothus Concha, a variety of Rhododendrons, Choisya Aztec Pearl, Pieris forest flame...
lots to choose from scroll down to the bottom of the page click on 'C' and then 'container plants'

I don't know of any evergreens that flower for a long time especially facing north. I would go for attractive foliage and put some fibrous rooted begonias round them for the warmer months - reliable colour whatever the aspect or the weather. I would avoid conifers though, in your situation.

I agree with Moongrower, that Pieris Forest Flame or one of the euonymus would be a good choice, as you would have plenty of colour from the leaves alone, and you also have the lovely colours of the new spring growth and flowers with the Pieris. You could put some heuchera around the base of it, or some pansies or polyanthus. Choisya Sungold would also be good, especially in a sunny site, as they stay a lovely bright golden yellow most of the year.
I also live in Cumbria, in Barrow-in-Furness, so we get less rain than elsewhere in the county, but we still get plenty of strong winds, otherwise I would have suggested acers. They don't like winds at all, and like to be in a sheltered sight--I've had to move mine!!