Var.: Май холодный - не будешь голодный
Cf: A cold April and a wet May fill the barn with grain and hay (Am.). A cold May and a windy makes a full barn and findy (Br.). A dry March, wet April and cool May fill barn and cellar and bring much hay (Br.). A fall of snow in May is worth a ton of hay (Am.)Русско-английский словарь пословиц и поговорок. Академик.ру. 2013.