Britain has many summer visitors. Amongst the most common are:
Swallows; House Martins and Sand Martins; Terns and most Warblers
(e.g. Reed, Sedge, Willow Grasshopper and Garden Warblers and
Whitethroat, Lesser Whitethroat).
Some, like Chiffchaff and Blackcap used to be summer visitors
but now sometimes overwinter in Britain.