Blackthorn Winter refers to a period of cold weather that typically occurs in late March or early April in the British Isles. It is characterized by a sudden drop in temperatures, often accompanied by frost and snow, despite the arrival of spring. The name comes from the blackthorn tree, which is known to bloom with white flowers around this time, often just before the cold snap. This weather phenomenon is part of the broader pattern of seasonal changes and can impact agriculture and wildlife. Farmers may need to protect young crops from frost damage, while animals may alter their behavior in response to the unexpected chill.