How many swallows make a Summer?

I'm not posting this for it's photographic qualities but to record my first sighting of this year's swallows. I knew they had arrived as a number of people have seen them in the village but they are my first! The day improved considerably from this morning and the afternoon walk was very pleasant. There were around 20 swallows congregating on the wires down the lane , skimming the skies before landing.
Busy morning in Oxfam and I left a little later than usual this afternoon. Having problems with internet connection and also mobile phone. What is going on 'up' there, is it the weather , is it me??