The Met Office forecasts a significant shift in conditions after a period of warmer weather. Heavy rain and thunderstorms are expected to move across the UK on Monday, affecting the whole country, according to the forecaster. The change follows a recent heatwave, with the outlook turning toward unsettled weather and periods of downpours. Multiple reports highlight the same warning that rain is likely to spread widely rather than remain localised, with thunderstorms included in the expected conditions. While exact timing and the severity of rainfall can vary by region, the overall message from the Met Office is that Monday brings a more disruptive weather pattern, including thunderstorms alongside heavy rainfall. The reports indicate the change is nationwide, reflecting a broader weather system passing through rather than isolated storms.