It is a good time now to prune rambling and climbing roses. This is done to reduce congestion in the plant and open it up so that air can flow, reducing the likelihood of disease. It is also done to encourage flowering all over the plant - not just at the top.
Ramblers - to reduce size prune out a third of the mature stems. If the plant is ok in size then just trim back side shoots to an outward facing bud.
Climbers - pull main stems down to a 45° angle and tie in. Cut upright stems to one or two buds above the main stem.
For both plants, cut out any dead or diseased wood. Stand back to check shape and cut out anything that doesn’t look right. Finally, mulch the plants with compost or well-rotted manure. If the plants are dry, water well first.