Elizabeth Line. Photo: Ceri Breeze / Shutterstock.com Transport for London (TfL) has issued a travel warning for Tuesday, June 23, through Thursday,June 25, 2026, as very high temperatures are expected to disrupt parts of the capital’s transport network, with delays and service changes already affecting multiple Tube and rail lines.
TfL said extreme heat conditions may impact services across London, particularly the London Overground and the Elizabeth line, where delays and partial suspensions are expected during the hottest parts of the day. Passengers have been advised to plan ahead and expect longer journeys across the network.
As part of its travel guidance, TfL urged passengers to carry water, allow extra time for journeys and, where possible, travel outside peak periods to avoid the busiest and hottest conditions. The authority also noted that bus services are expected to run normally despite the wider disruption on rail services.
Several Underground lines are already experiencing issues. The Circle line has been suspended across the entire route, while the District line is facing severe delays. The Elizabeth line is also affected, with disruption reported across key sections including Reading to Paddington and Whitechapel to Shenfield, alongside partial suspensions on Heathrow branches.
The Metropolitan line is operating with a mix of minor and severe delays depending on the section, while the Bakerloo line is reporting minor delays between Harrow & Wealdstone and Queen’s Park. The Mildmay line is also experiencing minor delays across its full route.
Other services are seeing more significant disruption. The Tram network is reporting severe delays on sections including Sandilands to Beckenham Junction and Sandilands to Elmers End. Most other lines are currently reporting good service, though conditions remain subject to change.
TfL said the combination of high temperatures and increased passenger demand can place additional strain on infrastructure, affecting rail signalling, tracks and rolling stock performance. Heat-related speed restrictions are also likely in some areas to maintain safety.
Looking ahead, TfL’s service outlook shows limited availability across several lines in the coming days, with continued monitoring in place as the heatwave persists.
Transport officials continue to monitor conditions closely and are advising passengers to check live updates before travelling, as disruption may change throughout the day.