The Pagan Book of Days for Thursday, May 11
The days of the Eisheilige (ice saints), May 11 – 15, are noted in southern Germany as the time when the presence of these “Strong Lords” bring unseasonably cold and/or wet weather. These are the saints Mamerius, Pancratius (Pancras)Servarius, Bonifathus, and Cold Sophie. The names of these saints are Christianized versions of the Swabian presiding spirits of the days.
Source
The Pagan Book of Days
Nigel Pennick
Witches Of The Craft® 