They're usually last seen in September or early October.
A growing number of swallows are choosing not to leave Ireland during the winter months.
The birds are normally last seen here in September or early October and stay in Africa until April or May before they return for summer.
However, sightings are now being seen in Wexford, Cork and Clare over winter.
Niall Hatch from Birdwatch Ireland has been speaking to Midlands 103's Ellen Butler about the significance of such a development: