Torrential rain and flash flooding has caused travel chaos across parts of the county after half a month's rain fell in just a few hours.

Watford is one of the worst hit areas, which has amber warnings in place, according to the Met Office.

Proper rain, lightning & thunder - the calls have started ! #Drive safe if you are #StaySafe https://t.co/HxImv0gIyo pic.twitter.com/ytyD34v5vZ

— Red Watch Watford (@redsfirewatford) September 16, 2016

Pictures on social media show severely waterlogged rail stations and roads. Firefighters were called Peace Hospice Care in the early hours after reports of flooding.

A train has also derailed at Watford Junction causing long delays.

The M25 anticlockwise is also closed due to flooding and an accident between J21A St Albans and J21 M1. 

Turnpike Lane and Manor House on the Piccadilly line were closed early on Friday but re-opened around 6.20am, Transport for London (TfL) said.

Met Office meteorologist Martin Combe said 32.8mm of rain had fallen in just three hours - nearly half the 70mm average for September.

The weather front is due to send temperatures tumbling ahead of the weekend, just days after parts of the county baked in 34C (93F) heat.

There were reports of roads and properties being inundated across Hertfordshire as a band of torrential rain moved in from the Channel overnight.

Hertfordshire Fire and Rescue Service said it had been called to reports of a flooding in Bovingdon, specifically Green Lane and Ryder Close (below).

Fire chiefs advised motorists to avoid driving through flooded roads and turn around as pictures emerged of Maidenhead High Street resembling a swimming pool.

Away from the storms, Friday will be a relatively cool and fresh day for most of the country with some sunshine.

Have you got any pictures of video? Email charlotte.ikonen@london.newsquest.co.uk.