Canals have been left running dry across England and Wales as Britain continues to bake in what could become its hottest summer ever. The forecaster issued a rare 15-hour amber 'extreme heat' warning for southern and central England from 9am tomorrow – only its second such alert in four years. Dried-up areas of the canal network include the Montgomery Canal at Llanymynech, and the Grantham Canal at Cotgrave, Nottinghamshire. However, if the rest of August stays as warm as it has been in recent weeks, 2026 will become the hottest summer. Southern Water warned more than 100,000 people in Hampshire will be hit by shortages unless a ban on filling public swimming pools and other non-essential water uses is put in place.