St Hilary’s Day, the Coldest of the Year

English people came to look on St Hilary’s Day as the coldest day of the year. Chambers thought it might simply be because the day fell in the middle of the coldest month, or because the great frost of 1205, which lasted until 22 March and sent the price of corn soaring, began on it. He notes that in 1820 the day did prove the coldest of the year, when one thermometer fell to four degrees below zero Fahrenheit.