I’m sure it varies from place to place but I have seen Swifts in late April for each of the last 21 years that I have lived in Westhay and kept records. The last 5 years have been April 26,25,22,27,28. Most things are a bit later this year imo. There have been very large flocks of Swallows over the levels and moors in the last 4 days, clearly resting and feeding while still migrating. there were 60 outside my house at 7.00 this morning. In most years they are well into nesting by now.

Several over Ilminster this morning.

Each year they return earlier. As nice as it is, also a worrying real sign of climate change,
perhaps ?

Just seen my first Swift of the year over my house in Tonedale. Wellington.