London faces an unusual May heatwave that could make the capital warmer than tropical islands, with health alerts and TfL travel guidance in place
The capital is bracing for a striking and sustained rise in temperatures as an unprecedented May heatwave moves across southern England. Early readings have already climbed into the low 20s, and forecasters indicate a steady climb through the weekend. The Met Office forecasts a top of 30C on Saturday, with temperatures rising further on Sunday and into next week.
This situation has prompted national health agencies and transport authorities to issue precautionary messages: an alert window remains active until 5pm on Wednesday, and residents are being reminded to take straightforward precautions against heat-related risks.
To put the forecast in perspective, the capital could be warmer than several well-known holiday spots during the same period.
The Met Office guidance suggests London may exceed the temperatures expected in the Maldives (around 29C) and the Seychelles (near 28C), reaching levels comparable to Barbados. At the same time, national services such as TfL and the UKHSA (UK Health Security Agency) are preparing for extra demand on infrastructure and care systems.
Understanding the scope of the warnings and how to respond can help people stay safe as conditions evolve.
What the forecasts say
Forecasters are signalling sustained high temperatures across London and much of southern England, with a clear upward trend through the weekend and into early next week. The immediate outlook expects a peak of 30C on Saturday and around 31C on Sunday. Looking further ahead, the Met Office models currently indicate maximums of 33C on Monday and 34C on Tuesday. If those higher figures materialise, they would surpass the historic May record of 32.8C set in May 1922 in Camden Square. The forecast also notes that these temperatures would represent the warmest May days on record for the UK.
How hot could today and the weekend feel?
As the day progresses, temperatures in central locations have already passed the 20C mark early in the morning. The expected hourly climb means Londoners could see roughly a degree rise each hour until the late-afternoon peak. That steady increase can make outdoor tasks physically demanding, particularly for people who are not acclimatised. The Met Office also compares the capital’s expected readings with international destinations: forecast highs suggest London could outpace places including Los Angeles (around 24C) and several tropical islands during this spell.
Record-breaking potential
The possibility of reaching 33C–34C raises the prospect of rewriting May temperature records in the UK. The long-standing high for the month was 32.8C in May 1922, and models projecting similar or higher values place London in rare climatological territory. Even short-lived peaks of this magnitude can strain public services and infrastructure — from rail and road surfaces to electricity demand — which is why authorities are treating the outlook as more than a routine warm spell.
Health and transport warnings
National health officials have issued alerts designed to protect the most vulnerable. The UKHSA warns of a likely rise in deaths, particularly affecting people aged 65 and over or those with existing health conditions, and flags the possibility of increased pressure on all health and social care services. The alert window will remain in place until 5pm on Wednesday. Officials emphasise straightforward actions such as staying hydrated, avoiding strenuous activity during the hottest hours, and checking on isolated or elderly neighbours to reduce avoidable harms.
Advice from transport authorities
Transport for London has asked passengers to carry water when using the Tube and to plan journeys in case services are affected by the heat. Carl Eddleston, TfL’s Director of Streets & Network Operations, said the organisation has a comprehensive hot-weather plan and is ready to deploy resources to protect infrastructure and maintain services. He urged travellers to use TfL real-time tools such as status updates, Journey Planner and the TfL Go app for the latest information and to look out for one another while travelling.
Practical steps for the public
Even brief preparation can reduce risk during a heat event. Keep a bottle of water on hand, avoid crowded, poorly ventilated spaces during peak heat, and follow local service updates if you plan to travel. For those caring for elderly relatives or people with health conditions, taking simple measures — ensuring access to cool spaces, checking medication instructions, and keeping communication lines open — can make a meaningful difference. With forecasts indicating higher temperatures than some tropical destinations, sensible precautions will help households and services manage the unusual May heat.
