You got there Yorkie

Saint Mamertus - May 11th (from Lyon)
Saint Pancras - May 12th (also known as the gateway to Sheffield - or Brussels in the other direction)
Saint Servatius - May 13th (from Armenia but died in Maastricht)
Saint Boniface of Tarsus - May 14th (this is a different saint from the Crediton one)
Saint Sophia of Rome - May 15th (the Bulgarians named their city after her)
Collectively known as the ice saints whose saints days often correspond to a sudden unseasonal drop in temperatures in mid May. Which, at least in central Europe can often produce the last night frosts before spring and summer really kick in. This is more observable and better known in Germany than in England, though in the latter it's sometimes called the Blackthorn winter because it so often happens around the time the first blackthorn berries appear. Though it rarely leads to frosts in England this often happens here as I have found to my cost. The cold Sophie is often the worst. Thankfully the tomato plants are now in and the beans are sprouting

The ice saints or Eisheiligen are not always punctual - or the same strength every year. Over to you.