The warm weather seen during the early part of this week is set to give way to wetter, more unsettled conditions for the start of the early May bank holiday , in bad news for the millions of Britons heading away for the long weekend. While temperatures are expected to reach 25C in eastern England on Saturday, other parts of the country will see showers , with thunderstorms possible at times. But the weather will remain unsettled throughout the bank holiday weekend, and temperatures are expected to fall below 20C across the country by Monday. The Met Office deputy chief forecaster, Tom Crabtree, said: “By Friday, conditions are expected to become more unsettled, with rain and showers spreading in from the southwest, some of which could be heavy and possibly thundery.…