(CNN)Severe thunderstorms caused flash flooding across London on Sunday afternoon, sparking major transport delays.
London Metropolitan Police said the flooding had caused "severe disruption" on the North Circular Road, one of the major roads surrounding central London.
Several London Underground train stations were heavily flooded, disrupting services.
The "significant flooding" affected services across the transport network," a Transport for London (TfL) spokesperson said in a statement emailed to CNN.
Multiple stations on the rail network known as the Tube were closed, according to the TfL website.
"With multiple bus routes on diversion and some Tube and rail services affected and stations closed, we strongly advise that customers check for the latest information before they travel to ensure they have a safe and smooth journey," the TfL spokesperson said.
Two London-area hospitals, Newham University Hospital and Whipps Cross University Hospital, were affected by the rains.
A spokesperson for Barts Health NHS Trust told CNN in a statement that both hospitals are experiencing operational issues due to the heavy rainfall.
"We are working closely with our local partners to resolve the issues and maintain patient care and -- while services remain available for people in an emergency -- patients are asked to attend alternative hospitals where they can, to help us put solutions in place as quickly as possible," the spokesperson said.
In the Worcester Park area, social media video emerged of cars stuck in the floodwaters and rescue boats working in the area.
The London Fire Brigade said in a tweet that it had received hundreds of calls reporting flooding across London.
"We have now taken more than 600 calls to flooding incidents, including flooding to roads & properties, reports of ceilings collapsing & vehicles stuck in water. Crews used specialist water rescue equipment to rescue five people from a car stuck in flood water in #WorcesterPark," the brigade said.
CNN meteorologist Gene Norman said that the storms that erupted over London and southern England on Sunday came on the heels of record heat on Friday.
"That very warm air collided with an area of low pressure near northern France. This resulted the slow-moving storms the produced the deluges and prompted the UK Met Service to issue an Amber alert for storms with 75 to 100 millimeters (3 to 4 inches) of rain expected," he said. "A half-dozen flood warnings remain in effect as runoff causes rivers to rise. The heaviest of the rain should move out by Monday morning."
Norman said unofficial reports estimated some locations around London received 60-92 millimeters (2.3 to 3.6 inches) of rain in an hour on Sunday.
"The tell-tale signature of this kind of flooding is that the storms formed and moved repeatedly over the same areas, basically, raining faster than it can drain," he said.