Two separate fires have caused major travel disruption on roads and railways near St Albans and Watford this afternoon.

A goods vehicle fire - which broke out in the afternoon and was extinguished by 4.08pm today (July 19) - caused disruption on the M1 northbound between Luton and Dunstable, with tailbacks to junction 7 for St Albans.

A fire next to the railway in Harrow has caused damage to overhead lines between London Euston and Watford Junction, with all trains suspended on the route.

Avanti West Coast, which runs trains between London Euston and North Wales, the North West and Scotland, has cancelled services for the rest of today due to "extreme heat".

The heat today has broken UK temperature records with a 40.2C high recorded at London Heathow Airport at 12.50pm, just 10 miles from the Hertfordshire border at Maple Cross.

This was broken again at Coningsby in Lincolnshire according to the Met Office's provisional results - with a 40.3C reading.

The previous record stood at 38.7C, recorded at Cambridge University Botanic Gardens in 2019.

The Bedford weather station recorded a 39C reading at 4pm.

Herts Advertiser: Traffic on the M1 between St Albans, Hemel Hempstead and Luton at around 4.25pm today (July 19)Traffic on the M1 between St Albans, Hemel Hempstead and Luton at around 4.25pm today (July 19) (Image: National Highways)

An earlier National Highways statement on the M1 fire read: "Lanes one and two are closed on the M1 northbound between J10 (Luton) and J11 (Dunstable) due to a goods vehicle fire.

"Frew crews have extinguished the fire and recovery is on scene.

"There are six miles of congestion on approach causing 40 min delays above normal travel time."

A Traffic England map shows traffic is moving through the area again, and all lanes reopened by 5.08pm.

Disruption on the railway line between London Euston and Watford Junction means trains travelling into London must terminate at alternative stations - including Milton Keynes in Buckinghamshire, Northampton, and Rugby in Warwickshire.

A Network Rail statement reads: "Passengers are being advised not to travel with all trains suspended between London Euston and Milton Keynes as Britain records its hottest day in history.

"The emergency services are dealing with a line side fire caused after 25,000 volt overhead electric cables which power trains came down in Harrow."

Herts Advertiser: Trees and scrub burnt next to electrified railway lines at Harrow, near the London-Hertfordshire borderTrees and scrub burnt next to electrified railway lines at Harrow, near the London-Hertfordshire border (Image: Network Rail)

James Dean, the route director, said: "As predicted, the extreme temperatures have impacted the overhead cables on the West Coast Main Line and all trains have had to be stopped.

"Please follow our 'do not travel' message today as journeys are being severely impacted. Once the emergency services give us the go ahead we will work as fast as we can to restore the railway lines.

"We're sorry to people impacted and we're working as fast as we can to get things back up and running."

Disruption is likely to continue for the rest of today, although the London Overground is able to run between Euston and Watford with "minor delays".

An Avanti West Coast spokesperson said: "Due to the extreme heat causing multiple incidents across the network, all Avanti West Coast services have now been withdrawn for the rest of Tuesday.

"Customers with tickets for today can use them tomorrow (July 20) or Thursday (July 21), or claim a full refund from their point of purchase."

There is disruption on other railway lines in Hertfordshire, with no Thameslink or Great Northern trains running anywhere in the county.