We experienced a long winter with cold temperatures and snow extending into the spring months. This is extremely hard on the bees, who need warm days to exit the hives to clean themselves and to gather their honey ingredients. Cold temperatures force the bees to gather closely to warm themselves, and if a cold spell is prolonged they will literally starve themselves trying to keep warm while only inches away from an abundant food supply.
Areas in Europe and in the U.K. also had long winters with record low temperatures in March and April. As reported in the BBC, this long cold winter has contributed to massive bee colony collapses. BBC report here.