Pressure is falling on Monday, the wind direction is changing and a weather front is moving down from the north-west, signalling a change to cooler and fresher weather.
The weather front, which is mainly a band of cloud with a few showers, will sweep across England and Wales. Sunny spells will follow. Temperatures will peak at 25C in south-east England.
Cooler and less humid air follows the band of cloud.
Another band of heavier rain will develop in Northern Ireland on Monday morning then spread across to Scotland and Cumbria in the afternoon.
Accompanied by strong and gusty southwesterly winds, the rain will limit temperatures to around 17C in Scotland and Northern Ireland.