LONDON –  British Prime Minister David Cameron is set to see firsthand the devastation caused by weeks of heavy rains and swollen rivers in northern England.

He plans to tour the region Monday as flood waters in some areas seem to have peaked, although more rain is forecast for the middle of the week.

Major cities including York, Leeds and Manchester have been affected in a wide area roughly 200 miles (320 kilometers) north of London.

British troops have been helping emergency workers and local residents in a widespread evacuation of towns and cities. Thousands of people have lost power in recent days as the situation worsened.

The Environment Agency has issued 24 “severe” flood warnings — meaning lives are at risk — and several hundred less dire alerts.